DE202010006145U1 - System for testing ropes - Google Patents

Abstract

A system for optically testing a rope (10) comprising:
- At least one image data acquisition device (24) which is designed to optically detect at least a portion (30) of the rope (10);
A setpoint value memory unit which is designed to setpoint the longitudinal extent K _{0 of} the strands (12, 12a) and / or the longitudinal extent J _{0 of} the wires (16, 16a), in particular relative to the longitudinal extent K _{0 of} the strands (12, 12a) To provide a discrimination unit;
An image data evaluation unit which is designed to have a longitudinal extent K _{m of} the strands (12, 12a) in the detected portion (30) of the rope (10) and / or the longitudinal extent J _{m of} the wires (16, 16a) in the detected portion ( 30) of the rope (10), in particular relative to the determined longitudinal extent K _{m of} the strands (12, 12a) to determine;
- the discrimination unit which is designed
At least one quality value by means of a quality standard as a function of the determined longitudinal extent J _{m of} the wires (16, 16a) and the nominal values of the longitudinal extent J _{m of} the wires (16, 16a) and / or;

Description

The The present invention relates to a system for testing ropes and to a computer program product.

ever according to the field of application, ropes are exposed to different loads. For example, ropes are in operation at cable cars, cranes or elevators via roles or they are deflected by discs. This is the rope with the individual wires primary with tensile and secondary claimed with bending and torsional stresses. Especially running and standing ropes have a finite life for this reason.

Around the reliability of the ropes, in particular ropes of cable cars, Bridges, Cranes or lifts, to ensure, are regular checks the ropes necessary. These controls can according to the prior art a include visual rope control by an employee.

outgoing It is an object of the known prior art to a system for testing to provide a rope, which is easier and safer to perform and which one improved test result achieved. The object is solved by the features of the independent claims. preferred Embodiments are Subject of the dependent Claims.

Method of testing

• – Bereitstellen eines Bilddatensatzes zu zumindest einem Abschnitt des Seils;
• – Bereitstellen von Sollwerten einer bildlichen Längserstreckung J₀ der Darstellung von Drähten relativ zu einer bildlichen Längserstreckung L des Seils in dem Bilddatensatz;
• – Bestimmen einer bildlichen Längserstreckung J_m der Drähte in dem Bilddatensatz, wobei das Bestimmen ein Anpassen einer angenommenen Längserstreckung an den Bilddatensatz umfaßt;
• – Bestimmen zumindest eines Gütewertes mittels einer Gütenorm als Funktion der bestimmten bildlichen Längserstreckung J_m der Drähte und der Sollwerte der bildlichen Längserstreckung J₀ der Drähte;
• – Diskriminieren von bildlichen Positionen innerhalb des Bilddatensatzes des Seils, an denen zumindest ein Gütewert einen vorbestimmten zugeordneten Gütegrenzwert überschreitet oder unterschreitet;
• – Bereitstellen der diskriminierten bildlichen Positionen.

An exemplary method for computer-aided optical testing of a rope comprises the steps of:

• Providing an image data set to at least a portion of the rope;
• Providing target values of a pictorial longitudinal extent J _{0 of} the representation of wires relative to a pictorial longitudinal extent L of the rope in the image data set;
• Determining a pictorial longitudinal extent J _{m of} the wires in the image data set, the determining comprising adapting an assumed longitudinal extent to the image data set;
• Determining at least one quality value by means of a quality standard as a function of the determined imagewise longitudinal extension J _{m of} the wires and the nominal values of the pictorial longitudinal extension J _{0 of} the wires;
• - Discriminating pictorial positions within the image data set of the rope, where at least one quality value exceeds or falls below a predetermined assigned quality limit value;
• - Provide the discriminated pictorial positions.

A optical rope control is based on the provided image data set possible, wherein advantageously a high physical stress of the one performing visual inspection Employee, for example, by spatially cramped jobs by physical Forced postures and poor seating positions, inadequate lighting conditions and weather conditions (Cold, Rain, wind, etc.) is avoided. Especially with a long test time can advantageously an impairment of the result of control due to a drop in concentration of the inspecting employee be avoided. The method can advantageously be anytime be interrupted and / or performed unattended.

The Providing the image data set may preferably be optical detection comprise at least a portion of the rope, in particular by means of an optical cable detection device, so that the optical detection advantageously possible during operation is. Further advantageously, the optical detection a threat to the performing Employee, for example, by moving parts such as rope, Pulley, rollers, etc excluded.

advantageously, is the provided or recorded image data set in electronic Form and is therefore by means of a corresponding archiving device permanently archivable. This changes the rope condition advantageously easy to recognize or understand. Next the archivability of the visual rope condition is the condition better objectively traceable or verifiable. For better archivability of the image data set the captured or provided images or raw image data preferably with suitable algorithms are stored in compressed form. The compression method can preferably be chosen so be that one random access to any rope position is possible, for example, by a piecewise JPEG compression together with a jump table in which the rope positions are indexed. This compression may already be during the acquisition of the image data take place so that one predetermined limited Data transfer rate to the storage medium is not exceeded.

Further advantageously possible the archivability of the image data set also the progress control the rope condition over the time. So it is conceivable that through Assignment of the same rope positions of different times recorded image data a temporal evolution of the rope condition or a defect can be observed.

Further Advantageously, the test method also used as so-called "inline control" when the calculation period of the observable to be evaluated, the computer power and the inline control allow this. The Rope parameters, setpoints and limit values can be stored upstream Configuration process are set.

The test methods may preferably comprise a 3D reconstruction. Since the rope geometry in The rule is well known, can be determined from the deviations the wire positions in a 2D image of the image data set on a Deviation of the rope geometry can be closed in three-dimensional space. This 3D rope geometry could then reconstructed to more precise visualization in three-dimensional space and shown as a model on a display device or a display become. The 2D image data of the image data set can in particular after a corresponding transformation used as a texture for this 3D model become.

The pictorial longitudinal extent J _m , J ₀ , J of the representation of wires in the context of the invention is understood to mean that an image of a wire contained in the image data record extends essentially along a preferred spatial direction, which is referred to as the longitudinal extent or length of the wire can. Wires of a cable preferably extend spatially along their longitudinal extent, in particular over several meters in length, while the width of wires is about 0.5 mm to about 6 mm. The image data set is provided to include an image of wires of a rope in which the longitudinal extent of wires of the rope or the longitudinal extent L of the rope substantially coincides with a direction spanning the image plane. The image of the wires or of the rope in the image dataset provided in this way thus likewise has a longitudinal extent that is for example greater than about 2, preferably greater than about 5, in particular greater than about 10, longer than the width of the image of the image Wire or rope in the image data set.

Of the Term "wire" in the sense The invention is not limited to a metal wire, but comprises also plastic fibers, which to form a plastic rope used or natural fibers. The term "wire" within the meaning of the invention is accordingly as "wire or fiber, in particular plastic or natural fiber "to read. The term "rope" therefore includes in addition to wire ropes also plastic ropes, fiber ropes and so on.

The provision of desired values of the pictorial longitudinal extent J _{0 of} the representation of wires can be effected by means of a database, by reading out a data carrier or by means of a user input. The setpoint values of the pictorial longitudinal extension J ₀ can include setpoints, setpoint positions and / or desired directions of the image of wires relative to the pictorial longitudinal extent L of the cable in the image data set. Advantageously, the reference of the set values to the pictorial longitudinal extent L of the rope permits an accurate definition of set points, set positions and / or set directions even in the event that the length L of the rope in the image data set does not have a predetermined direction and / or position.

In particular, the setpoint values of the pictorial longitudinal extent J _{0 of} the representation of wires may include a wire angle β of one or more wires, wherein the wire angle β may be defined as the angle between the set value of the pictorial longitudinal extent L _{0 of} the rope and the set value of the longitudinal extent J _{0 of} the wires is included. Since a fault-free rope can be assumed for the nominal values, the wire angles β for all wires can be predetermined by the type of rope. For example, the wire angles of adjacent wires may be substantially equal, that is, adjacent wires are disposed substantially parallel to each other and imaged in the image data set substantially parallel to each other.

Preferably, the setpoint values of the pictorial longitudinal extension J _{0 of} the representation of wires may also include an expected target start and / or target end position of one or more wires. The Sollanfang- or Sollendposition can define the beginning or the end of the visible in the image data set longitudinal extent J _{0 of} the wires. Alternatively or additionally, the setpoint values may also comprise further setpoint positions of one or more wires of the cable, such as a geometric center point or an inflection point of the longitudinal extent of the wires visible in the image data set.

Preferably the step of determining the spatial extent of the wires in the detected portion of the rope by adjusting an assumed longitudinal extension of the wires to areas of the image data set with high brightness values. A high brightness value for example, is a brightness value that is above the mean of all the rope relevant brightness values of the image data set is.

Determining the actual pictorial longitudinal extent J _{m of} the wires in the image data set is determined by fitting, in particular by an iterative fitting or fitting. To adjust the nominal values of the pictorial Longitudinal extension J ₀ of wires can be assumed as initial starting values for an assumed longitudinal extension. The fitting involves determining image information of the image data set existing at the position of the assumed longitudinal extent and changing the assumed longitudinal extent in order to minimize a deviation between the image information present at the assumed longitudinal extent and expected image information. For example, the setpoint values of the pictorial longitudinal extent J _{0 of} the representation of a wire can relate to the wire center line, so that, for example, higher brightness values are to be expected at the locations of the image data set on which the wire center line is located than at the boundary lines between two adjacent wires. Starting from the pictorial longitudinal extent J ₀ according to the nominal values, the actual longitudinal extent J _m can be determined by adapting the assumed longitudinal extent by means of the image data set.

According to the method, on the basis of and the provided set values of the pictorial longitudinal extension J _{0 of} the wires and the fitting determined longitudinal dimension J _{m of} the wires, at least one quality value is calculated, which indicates to what extent the actual longitudinal extent J _m of the set value of the pictorial longitudinal extent J ₀ deviates. Therefore, the determination of the quality value may include comparing the determined pictorial longitudinal extent of the wires with the set values of the pictorial longitudinal extent of the wires. The quality value can be determined by means of a quality standard as a function of this comparison, ie as a function of the determined pictorial longitudinal extent J _{m of} the wires and the nominal values of the pictorial longitudinal extension J _{0 of} the wires. As quality standard, different distance norms, confidence values or statistical key figures can be used.

On The basis of the at least one specific quality value is a discrimination of pictorial positions within the image data set of the rope, where at least one quality value exceeds a predetermined assigned quality limit value or below. The over- or below a property limit value may be associated with a potential rope error, so that the discrimination also a discrimination regarding the presence of a rope fault or a certain rope fault may include.

The Result of the discrimination is provided, besides the Indicating that a quality threshold within the image data set. or falls below, including the overshoot or undershoot attributable or assigned pictorial position can be provided. Next, the pictorial position within the image data set with a spatial Linked position be, so that alternatively or additionally the spatial Positions can be provided where an over- or Fall below the quality limit occurs. It is understood that in case that with respect to two or more loyalty values was discriminated against, the information will also be provided can indicate which of the guideline values was not complied with and in particular which of the Gütegrenzwerte associated cable fault has occurred. Providing the result can in particular a storage on a disk, a Displays on a display device, printing a test report and a transmission to an external device, for example via an interface in the form of a data stream.

• – Bereitstellen von Sollwerten der bildlichen Längserstreckung K₀ der Darstellung von Litzen relativ zu der bildlichen Längserstreckung des Seils in dem Bilddatensatz;
• – Bestimmen der bildlichen Längserstreckung K_m der Litzen in dem Bilddatensatz, wobei das Bestimmen ein Anpassen einer angenommenen Längserstreckung an den Bilddatensatz umfaßt;
• – Bestimmen zumindest eines Schlaggütewertes mittels einer Schlaggütenorm als Funktion der bestimmten bildlichen Längserstreckung der Litzen und der Sollwerte der bildlichen Längserstreckung der Litzen.

Preferably, the method further comprises the steps of:

• Providing target values of the pictorial longitudinal extent K _{0 of} the representation of strands relative to the pictorial longitudinal extension of the rope in the image data set;
• Determining the pictorial longitudinal extent K _{m of} the strands in the image data set, the determining comprising adapting an assumed longitudinal extent to the image data set;
• Determining at least one impact quality value by means of a impact quality standard as a function of the determined pictorial longitudinal extent of the strands and the nominal values of the pictorial longitudinal extension of the strands.

preferred to be tested Objects are stranded cables, in particular stranded wire ropes whose strands spirally are arranged around a rope insert around. The strands in turn include a strand insert around which a plurality of wires are spirally arranged are.

Under the pictorial longitudinal extent the representation of strands in the sense of the invention is understood that yourself an image of a strand contained in the image data set substantially extends along a preferred spatial direction, which as a longitudinal extension or longitudinal direction the strand can be designated. Just like the wires of a Ropes extend strands spatially preferably along its longitudinal extent, especially over several Meter length, while the width of strands is about 1 mm to about 30 mm. Becomes the image data set provided as described above, the falls longitudinal extension one of the spiral arranged strands at least partially substantially with a direction spanning the picture plane.

The provision of desired values of the pictorial longitudinal extension K _{0 of} the representation of strands can be done by means of a database, by reading a data carrier or by means of a user input. The setpoint values of the pictorial longitudinal extent K ₀ can include setpoints, setpoint positions and / or desired directions of the image of strands relative to the pictorial longitudinal extent L of the rope in the image data set. Advantageously, the reference of the set values to the pictorial longitudinal extent L of the rope permits an accurate definition of set points, set positions and / or set directions even in the event that the length L of the rope in the image data set does not have a predetermined direction and / or position.

In particular, the setpoint values of the pictorial longitudinal extent K _{0 of} the representation of strands may include a bounce angle α of one or more strands, wherein the bounce angle α may be defined as the angle between the desired value of the pictorial longitudinal extent L _{0 of} the rope and the set value of the longitudinal extent K _{0 of} the strands is enclosed. Since a fault-free rope can be assumed for the nominal values, the impact angles α for all strands can be predetermined by the type of rope. For example, the impact angles of adjacent strands may be substantially equal, that is, adjacent strands are disposed substantially parallel to one another and imaged in the image data set substantially parallel to each other. As an alternative or in addition to the impact angle α, a lay length S of one or more strands can also be provided as desired value (e). The lay length S indicates after which distance along the longitudinal direction L of the rope, a strand has completed a complete wrapping of the rope insert. The lay length S can also be determined by means of the strand thickness and the number of strands by multiplying the two sizes.

Preferably, the nominal values of the pictorial longitudinal extent K _{0 of} the representation of strands may also include an expected target start and / or target end position of one or more strands or of one or more borderlines between adjacent strands. The Sollanfang- or Sollendposition can define the beginning or the end of the visible in the image data set longitudinal extent K _{0 of} the strands. Alternatively or additionally, the setpoints may also include other desired positions of one or more strands of the rope, such as a geometric center, an inflection point of the longitudinal extent of the strands visible in the image data set, or points on the boundary line of one of the strands to an adjacent strand.

Preferably, the step of determining the spatial extent of the strands in the detected portion of the cable is done by adjusting the assumed longitudinal extent K _{m of} the strands to areas of the image data set with low brightness values. A low brightness value is, for example, a brightness value which is below the mean value of all brightness values of the image data record relating to the cable.

The determination of the actual pictorial longitudinal extent K _{m of} the strands in the image data set is determined by fitting, in particular by an iterative fitting or fitting. For adaptation, the nominal values of the pictorial longitudinal extent K ₀ of strands can be assumed as initial starting values for an assumed longitudinal extent. The fitting involves determining image information of the image data set existing at the position of the assumed longitudinal extent and changing the assumed longitudinal extent in order to minimize a deviation between the image information present at the assumed longitudinal extent and expected image information. For example, the setpoint values of the pictorial longitudinal extension K _{0 of} the representation of a strand may relate to the boundary line of this strand to an adjacent strand, so that lower brightness values are to be expected at the points of the image data set at which the boundary line of the strand is due to a shadow cast at the places surrounding the border. Starting from the pictorial longitudinal extent K ₀ according to the nominal values, the actual longitudinal extent K _m can be determined by adapting the assumed longitudinal extent by means of the image data set.

According to the method, the impact quality value G _S can be calculated on the basis of the provided desired values of the pictorial longitudinal extension K _{0 of} the strands and the imagewise longitudinal extent K _{m of} the strands determined by means of adaptation. The impact quality value G _S indicates the extent to which the actual longitudinal extent K _m deviates from the nominal value of the pictorial longitudinal extension K ₀ , for example by a variation of the lay length S or the impact angle α. Determining the impact quality value G _S may include comparing the determined pictorial longitudinal extent of the strands with the set values of the pictorial longitudinal extension of the strands. The impact quality value G _S can be determined by means of the impact quality standard as a function of this comparison, ie as a function of the determined pictorial longitudinal extension K _{m of} the strands and the nominal values of the pictorial longitudinal extension K _{0 of} the strands. As impact standard, different distance norms, confidence values or statistical key figures can be used.

Preferably, the provision of set values of the pictorial longitudinal extent J _{0 of} the representation of wires relative to the pictorial longitudinal extent of the strands in the image data set is effected. More preferably, the determination of the pictorial longitudinal extent J _{m of} the wires takes place in the image d Tensatz relative to the particular longitudinal extent of the strands.

As already stated, the setpoint values of the pictorial longitudinal extension J _{0 provided for} the representation of wires, for example set points, desired positions and / or desired directions of the image of wires relative to the pictorial longitudinal extent L of the cable, can be indicated in the image data set. For the preferred case of testing a stranded cable, these setpoint values of the longitudinal extent J _{0 can} alternatively or additionally be specified relative to a nominal value of the longitudinal extent K _{m of} one or more strands. Advantageously, the reference of the nominal values to the pictorial longitudinal extent K _{m of} the strand enables an exact definition of nominal points, nominal positions and / or desired directions even in the case where the actual longitudinal extent K _{m of} the strand relative to the longitudinal extent L of the rope in the image data set does not reach a predetermined one Direction and / or position has. Advantageously, in particular cases can be distinguished, in which a strand as a whole is not in the desired position, but the longitudinal extent of the wires within the strand corresponds to their desired positions, of such cases, in which additionally deviations in the longitudinal extent of the wires in terms of Setpoints occurs.

In particular, the setpoint values of the pictorial longitudinal extent J _{0 of} the representation of wires may comprise a wire-strand angle γ of one or more wires, wherein the wire-strand angle γ may be defined as the angle which exists between the nominal value of the pictorial longitudinal extent K _{0 of} the strand and the set value of the longitudinal extent J _{0 of} the wires is included. In a faultless strand, the wire-strand angles γ may preferably be constant for all wires, that is, the adjacent wires are arranged substantially parallel to each other.

• – als Funktion eines geometrischen Abstands zwischen der bestimmten bildlichen Längserstreckung J_m der Drähte und der Sollwerte der bildlichen Längserstreckung J₀ der Drähte und/oder
• – als Funktion eines geometrischen Abstandes zwischen den bestimmten bildlichen Längserstreckungen J_m zumindest zweier benachbarter Drähte bestimmt wird.

Preferably, the at least one specific quality value comprises a geometry quality value G _G , which is determined by means of a geometry gauge standard

• As a function of a geometrical distance between the determined pictorial longitudinal extent J _{m of} the wires and the nominal values of the pictorial longitudinal extension J _{0 of} the wires and / or
• - Is determined as a function of a geometric distance between the specific pictorial longitudinal extents J _m at least two adjacent wires.

Preferably, based on the provided set values of the pictorial longitudinal extent J _{0 of} the wires and the actual pictorial longitudinal extent J _{m of} the wires determined by fitting, the geometry _quality value G _G can be calculated. The geometry quality value G _G preferably indicates to what extent the actual longitudinal extent J _m deviates from the desired value of the pictorial longitudinal extension J ₀ . The geometry quality value G _G can be determined, for example, by determining a Euclidean distance as the preferred geometric shape standard between the two longitudinal extents and / or between excellent points within the two longitudinal extents. Alternatively or additionally, the geometry of geometry standard may also include a difference of the wire angle according to one of the desired values and a certain actual wire angle.

The geometry quality value G _G can preferably also indicate to what extent the actual longitudinal extent J _{m of} two adjacent wires deviates from one another or from a corresponding desired value of the pictorial longitudinal extension J ₀ . For example, the geometry gauge G _G may include a difference of the determined wire angles according to the determined actual longitudinal extensions J _{m of} two or more adjacent wires. For example, a variation of the wire angle may indicate a displacement of two adjacent wires.

Preferably, the method further comprises the step of determining a brightness distribution function along the determined pictorial length of the wires, wherein the at least one determined quality value comprises a quality of continuity value G _s determined by a quality of continuity as a function of the brightness distribution function, the first derivative of the brightness distribution function and / or the second Derivation of the brightness distribution function and / or its n-th order moments with n = 0, 1, 2 is determined.

Preferably, the determined pictorial longitudinal extent J _{m of} one of the wires is parameterized by a continuous line between two end points. More preferably, the continuous line is chosen such that the course of the line substantially coincides with the center line along the wire. One of the values contained in the image data set, for example the brightness value of the image, is determined along the line or along a predetermined width band in which the line is located, thus resulting in the brightness distribution function along the line.

Preferably, the resulting brightness distribution function of error-free wires is essentially a constant function, which can only be characterized by an average of the brightness values. A fault of the wire can lead to a variation of the brightness distribution function. For example, a breakage of the wire may lead to an intervalwise change in the co-efficient value of the brightness distribution function. In other words, the brightness distribution function may, for example, include an interval in which the brightness distribution function has lower values, for example values reduced by 50 percent compared to the values surrounded by the interval or values close to zero. These exemplary deviations can be characterized by the first and / or second statistical moment. Preferably, the continuity quality value may include the variance or the mean variance of the brightness distribution function.

When another example Notches or local damage (eg by lightning strike) in the wire to an irregular brightness distribution function to lead. Such irregularities can be, for example to interval changes in the first and / or second derivative of the brightness distribution function to lead, which is due to a local change of the mean value in the first and second derivative, respectively. These changes in the derivatives can preferably by the first and / or second statistical moment of respective derivative are characterized. Preferably, the Continuity quality value the variance or mean variance of the first or second derivative of the Include brightness distribution function.

Especially Preferably, by means of a continuity quality standard, which is based on the mean and / or the variance of the brightness distribution function, the first derivative of the brightness distribution function and / or the second derivative of the brightness distribution function is a deviation of the particular brightness distribution function from an expected target distribution of the brightness distribution function be characterized. For example, the continuity quality standard may be a weighted one Sum of the mean values and / or variances of the brightness distribution function or their derivatives include.

• – Bestimmen des lokalen bildlichen Durchmessers D_m des Seils in dem Bilddatensatz;
• – Bereitstellen von Sollwerten des lokalen Durchmessers D₀;
• – Bestimmen eines Durchmessergütewertes mittels einer Durchmessergütenorm als Funktion des bestimmten bildlichen Durchmessers D_m und der Sollwerte des lokalen Durchmessers D₀.

Preferably, the method further comprises the steps of:

• - determining the local pictorial diameter D _{m of} the rope in the image data set;
• Providing target values of the local diameter D ₀ ;
• Determining a diameter quality value by means of a diameter quality standard as a function of the determined pictorial diameter D _m and the setpoint values of the local diameter D ₀ .

The local dihedral diameter D _{m of} the rope may be limited to a portion along the length of the rope in the image data set, for example to a length of about 20 or about 100 pixels or to a corresponding length of the actual rope of about 10 mm or about 50 mm ,

The determination of the local diameter D _m takes place along a diameter direction perpendicular to the longitudinal extension or longitudinal direction L of the cable. Preferably, the diameter can be determined by a distance determination of two sheaths of the cable extending along the longitudinal extension or longitudinal direction L. The envelopes can be determined, for example, by a Hilbert transformation of the two cable contour lines.

The setpoint value of the local diameter D ₀ provided is preferably constant over the entire cable length. Preferably, the diameter quality value G _D can be calculated on the basis of the setpoint value (s) provided and the determined actual local diameter D _m . The diameter quality value G _D preferably indicates to what extent the actual local diameter D _m deviates from the nominal value of the diameter D ₀ , for example by means of the Euclidean distance between the two diameter values as preferred diameter quality standard. A variation of the diameter quality value G ₀ can, for example, indicate a widening or collapse of the rope.

• – Auswählen eines Bilddatensatzes;
• – Bestimmen von zumindest zwei Stützpunkten und einer durch die Stützpunkte definierte Verbindungslinie derart, daß die Verbindungslinie im wesentlichen zusammenfällt mit – einer Grenzlinie zwischen zwei benachbarten Litzen oder – einer Grenzlinie zwischen zwei benachbarten Drähten oder – einer Mittellinie einer Litze oder – einer Mittellinie eines der Drähte;
• – Abspeichern der Stützpunkte auf einem Speichermedium.

Preferably, the step of providing desired values of the spatial extension of the strands and / or the spatial extent of the wires comprises the following steps:

• - selecting an image data set;
• Determining at least two support points and a connection line defined by the support points such that the connection line substantially coincides with a boundary line between two adjacent strands or a borderline between two adjacent wires or a centerline of a strand or a centerline of one of the wires ;
• - storing the points on a storage medium.

Prefers can the setpoints based on a selected, in particular representative, image data set be determined. More preferably, one or more may Setpoint (s) to be determined on the basis of rope-specific manufacturer information, for example, due to a numerical rope model and the rope-specific characteristic sizes, e.g. B. rope diameter, strand number, strand diameter, winding type, Wire size, wire number, Diameter of the rope insert, diameter of the strand insert and so on further.

Preferably, at least two or more points are determined by which a Ver binding line is defined. The number of vertices may be 2, 3, 4, 5, 6, 7, or any other natural number. The connecting line may be defined between the interpolation points by linear or cubic interpolation. Furthermore, a spline can connect the interpolation points as a connecting line. However, the vertices may also define a regression line or a regression polynomial or other regression function, where the vertices need not be on the regression function.

The bases can in such terms be positioned of the image data set that through the support points defined connecting line with a borderline between two adjacent ones Strands or with a borderline between two adjacent wires or with a centerline of a strand or with a centerline of a strand Wire. Such a determined connection line can the longitudinal extent a wire and / or a strand and can as initial start value for adaptation and determination of an actual longitudinal extension be used.

Around the bases or to provide the connection line (s) to the test method as setpoint values, can the bases and / or preferably transmitting the connecting lines to a storage medium become.

Preferably comprises the method further comprises the step of assigning the quality value to the associated discriminated spatial Positions along the rope. Advantageously, cable sections be quickly found with potential identified rope faults, in particular, a visual check of this Cable sections on the rope itself and / or based on the pictorial representation to carry out the rope.

Further Preferably, the method may include the step of assigning a rating feature, in particular based on the at least one quality value, to the associated discriminated spatial positions along the rope. Exemplary rating features may be classifications the possible Rope errors include such. B. "wire breakage", "Litzenverwerfung", "notch", "lightning strike" etc. The Rating feature could Also include a score value that indicates the severity of the error or the determination certainty. In particular, a or multiple rating features included in an error log to be useful to a user of the method easy way to enable to detect the determined rope faults.

A computer program product

One Aspect of the present invention relates to a computer program product, especially embodied as a signal and / or as a data stream, which is computer readable Includes instructions the instructions being a method according to the invention, in particular as previously described, perform on an appropriate computer system loaded and executed become. In other words, a computer program product is provided which program parts to carry out the process of the invention or a preferred embodiment including it. Furthermore, a computer program is provided, which, if on a computer loaded, the method according to the invention or a preferred embodiment To run can. Furthermore, a computer-readable storage medium is provided, on which such a computer program is stored.

system

• – zumindest eine Bilddatenerfassungseinrichtung, welche ausgelegt ist zumindest einen Abschnitt des Seils optisch zu erfassen;
• – eine Sollwertspeichereinheit, welche ausgelegt ist Sollwerte der Längserstreckung K₀ der Litzen und/oder der Längserstreckung J₀ der Drähte, insbesondere relativ zu der Längserstreckung K₀ der Litzen, einer Diskriminierungseinheit bereitzustellen;
• – eine Bilddatenauswerteeinheit, welche ausgelegt ist, eine Längserstreckung K_m der Litzen in dem erfaßten Abschnitt des Seils und/oder die Längserstreckung J_m der Drähte in dem erfaßten Abschnitt des Seils, insbesondere relativ zu der bestimmten Längserstreckung K_m der Litzen, zu bestimmen;
• – die Diskriminierungseinheit, welche ausgelegt ist, zumindest einen Gütewert mittels einer Gütenorm als Funktion der bestimmten Längserstreckung J_m der Drähte und der Sollwerte der Längserstreckung J₀ der Drähte und/oder zumindest einen Gütewert mittels einer Gütenorm als Funktion der bestimmten Längserstreckung K_m der Litzen und der Sollwerte der Längserstreckung K₀ der Litzen zu bestimmen sowie die bildlichen Positionen innerhalb des Bilddatensatzes des Seils, an denen zumindest ein Gütewert einen vorbestimmten zugeordneten Gütegrenzwert überschreitet oder unterschreitet zu diskriminieren; und
• – eine Ausgabeeinheit.

One aspect of the invention relates to a system for optically testing a cable comprising:

• At least one image data acquisition device which is designed to optically detect at least a portion of the cable;
• A setpoint value memory unit which is designed to provide setpoint values of the longitudinal extent K _{0 of} the strands and / or the longitudinal extent J _{0 of} the wires, in particular relative to the longitudinal extent K _{0 of} the strands, of a discrimination unit;
• An image data evaluation unit which is designed to determine a longitudinal extent K _{m of} the strands in the detected section of the cable and / or the longitudinal extent J _{m of} the wires in the detected section of the cable, in particular relative to the determined longitudinal extent K _{m of} the strands;
• - The discrimination unit, which is designed, at least one quality value by means of a quality standard as a function of the determined longitudinal extent J _{m of} the wires and the setpoint values of the longitudinal extension J _{0 of} the wires and / or at least one quality value by means of a quality standard as a function of the determined longitudinal extent K _{m of} the strands and to determine the setpoint values of the longitudinal extent K _{0 of} the strands and to discriminate the pictorial positions within the image data set of the cable at which at least one quality value exceeds or falls below a predetermined assigned quality limit value; and
• - an output unit.

Preferably, the setpoint memory unit contains setpoint values of the pictorial longitudinal extent of the Representation of strands relative to the pictorial longitudinal extent of the rope in the image data set, wherein the image data evaluation unit is adapted to determine the pictorial longitudinal extent of the strands in the image data set, and wherein the discrimination unit is designed to at least one impact quality value G _S by means of a impact standard as a function of the determined to determine the pictorial longitudinal extent of the strands and the nominal values of the pictorial longitudinal extent of the strands.

Preferably, the setpoint memory unit includes setpoint values of the pictorial longitudinal extent J _{0 of} the representation of wires relative to the pictorial longitudinal extent of the strands in the image data set, the image data evaluation unit being adapted to determine the pictorial longitudinal extent J _{0 of} the wires relative to the determined longitudinal extent of the strands in the image data set ,

• – als Funktion eines geometrischen Abstands zwischen der bestimmten bildlichen Längserstreckung J_m der Drähte und der Sollwerte der bildlichen Längserstreckung J₀ der Drähte oder
• – als Funktion eines geometrischen Abstandes zwischen den bestimmten bildlichen Längserstreckungen zumindest zweier benachbarter Drähte bestimmt wird.

The discrimination unit is preferably designed to determine a geometry quality value G _G which is determined by means of a geometry gimbal standard

• As a function of a geometrical distance between the determined pictorial longitudinal extent J _{m of} the wires and the nominal values of the pictorial longitudinal extent J _{0 of} the wires or
• - Is determined as a function of a geometric distance between the specific pictorial longitudinal extents of at least two adjacent wires.

Preferably, the image evaluating unit and / or the discriminating unit are adapted to determine a brightness distribution function along the particular pictorial longitudinal extent of the wires, the at least one particular quality value comprising a quality of continuity value G _S determined by a continuity quality function as a function of the brightness distribution function, the first derivative of the brightness distribution function, and / or the second derivative of the brightness distribution function and / or its n-th order moments with n = 0, 1, 2 is determined.

Preferably, the setpoint memory unit is configured to provide setpoint values of the local diameter D _m , wherein the image evaluation unit and / or the discrimination unit are configured to determine the local pictorial diameter D _{m of} the rope in the image data set and wherein the discrimination unit is designed to use a diameter quality value G _D a diameter quality standard as a function of the specific pictorial diameter D _m and the setpoint values of the local diameter D to determine.

• – einen Bilddatensatz auszuwählen,
• – zumindest zwei Stützpunkten und einer durch die Stützpunkte definierte Verbindungslinie derart zu bestimmen, daß die Verbindungslinie im wesentlichen zusammenfällt mit – einer Grenzlinie zwischen zwei benachbarten Litzen oder – einer Grenzlinie zwischen zwei benachbarten Drähten oder – einer Mittellinie einer Litze oder – einer Mittellinie eines der Drähte und
• – die Stützpunkte auf einem Speichermedium abzuspeichern.

Preferably, the system comprises an input device enabling a user:

• To select an image data set
• To determine at least two support points and a connecting line defined by the support points such that the connection line substantially coincides with a boundary line between two adjacent strands or a boundary line between two adjacent wires or a center line of a strand or a center line of one of the wires and
• - Save the bases on a storage medium.

Preferably if the discrimination unit is designed, the assignment of the quality value to the associated discriminated spatial Perform positions along the rope. More preferably, the system comprises in particular the image data acquisition device, a rope feed measuring device.

Preferably comprises the system comprises a rope evaluation unit which is adapted to discriminated against by the discrimination unit spatial Assign a valuation characteristic to positions along the rope.

advantageously, can a human examiner all based on a log issued by the output unit get notified of potential rope faults and their position. A visual check can advantageously by the system according to the invention to a fraction the entire rope length be reduced. Next advantageously, the rope test is also improved in terms of occupational safety for the examiner concerned.

Fiqurenbeschreibung

following become preferred embodiments of the present invention with reference to the accompanying drawings by way of example explained. Individual features of the preferred embodiments shown may be added further preferred embodiments be combined. Show it:

1 a stranded rope as an exemplary rope;

2 : characteristic design sizes of a stranded rope;

3 a schematic preferred image data acquisition device;

3a a preferred image data acquisition device;

4 : a preferred step to Erfas sen of rope-specific setpoints;

5 a preferred step for acquiring rope-specific setpoints;

6 : exemplary specific setpoints;

7 a preferred automatic determination of the local diameter of the rope;

7a : exemplary specific local diameter of the rope;

8th a preferred automatic determination of lay length;

8a : exemplary determined local lay length of the rope;

9 an automatic detection of wire dislocations in an image data set;

10 : a preferred detection of wire breaks; and

11 : an exemplary result of the test procedure.

1 shows as a preferred rope 10 a stranded rope 10 as an exemplary wire rope. Stranded 10 include several strands 12 , which helically around a rope insert 14 are tortuous. The strands 12 consist of one or more layers of wires 16 , which helically around a strand insert 18 wound or stranded or beaten. The common term "hitting" is used synonymously for the term "stranding" in the following. The strand insert 18 may for example consist of a plastic fiber or a wire. The strands are preferred 12 from wires 16 and a strand insert 18 similar, preferably formed substantially the same diameter. Further preferred are for the formation of the strand 12 six wires 16 around the strand insert 18 arranged around. The rope insert 14 may consist of fibrous materials, in particular of plastic, or at least one wire or be formed in turn as a strand or rope. The stranded rope is preferred 10 made of strands 12 and a rope insert 14 similar, preferably formed substantially the same diameter. Further preferred are for the formation of the rope 10 four to ten strands 12 around the rope insert 14 arranged around. In the most preferred embodiment shown, there are six strands 12 around the rope insert 14 arranged around.

Ropes or stranded cables 10 the in 1 The types shown are used as running ropes, as standing ropes or as suspension ropes from various fields of technology. As "running ropes" while ropes are referred to, which run over traction sheaves, sheaves and drums and thereby take their curvatures, z. As hoisting ropes, pull-in ropes, ropes of cranes, elevator ropes, mop ropes and ropes of cable cars. "Standing ropes", also called guy ropes, cables are understood that do not run on sheaves and the ends are stored in fixed points, such as guy ropes for masts and booms and guide cables for lifts and shaft conveyor systems and anchor lugs for dredgers with and without windlasses. Ropes are ropes on which run, for example, rolls of funding, such as conveyors of cable cars, cable cranes and cable clamps. Supporting cables fulfill a similar function as running rails. The radius of curvature of a support rope under the caster is greater than the caster radius. It is understood that the different ropes can be made of different materials depending on the application, for example of plastic such as aramid, Dyneema, polyamide or steel, stainless steel or galvanized steel.

All rope types have specific, unique design patterns that can be detected in a digital image analysis. 2 illustrates the characteristic design variables of a stranded cable 10 , Perpendicular to a longitudinal direction L of the stranded rope 10 becomes the diameter D of the stranded rope 10 measured. Preferably, the diameter D by an optical detection of the stranded cable 10 and a subsequent distance determination of the two extending along the longitudinal direction L envelope 22a . 22b the associated detected strand rope contour lines 20a . 20b be measured. The envelopes 22a . 22b can, for example, by a Hilbert transformation of the detected Litzenseilkonturlinien 20a . 20b be determined.

Other characteristic sizes of the stranded cable 10 are the lay length S and the impact angle α of the strands 12 . 12a with respect to the longitudinal direction L. The lay length S describes the distance along the longitudinal direction L of the rope 10 a strand 12 a complete wrapping of the rope insert 14 has performed. The impact angle α may be defined as the angle which exists between the longitudinal direction L of the rope 10 and longitudinal direction K of the strand 12 is included. For a faultless rope, the longitudinal directions K of two adjacent strands 12 . 12a parallel to each other, so that the impact angle a as a characteristic size for all strands 12 . 12a can be used.

Another characteristic size of the stranded rope 10 is the wire angle b of each wire th 16 . 16a opposite to the longitudinal direction L of the rope 10 , The wire angle β may be defined as the angle which exists between the longitudinal direction L of the rope 10 and longitudinal direction J of the wires 16 . 16a is included. For a faultless rope, the longitudinal directions J of two adjacent wires 16 . 16a partially substantially parallel to each other. That is, the adjacent wires 16 . 16a adjacent to each other, in particular mechanically contacting, are wound around the strand insert. The wire angle β can therefore be the characteristic size for all wires 16 . 16a be used.

3 shows a schematic image data acquisition device 24 which is designed a rope 10 in an image data record. The image data acquisition device 24 In a preferred embodiment, 3 to 5, in particular 4, cameras 26a - 26d , which in a plane perpendicular to the longitudinal direction L of the rope 10 are arranged. The cameras 26a - 26d are preferably line scan cameras or CCD cameras. Each of the cameras 26a - 26d covers an associated quadrant of about 90 degrees of the cable jacket surface so that an image data set can be provided which includes the cable jacket surface in its entirety. The rope 10 is relative to the image data acquisition device 24 along or against the longitudinal direction L displaced. It is understood that in the case of a stationary rope and the image data acquisition device 24 can be moved. Preferably, the relative speed between rope 10 and cameras 26a - 26d be up to about 5 m / s.

The cameras are preferred 26a - 26d within the image data acquisition device 24 displaceable relative to the rope to the image data acquisition device 24 to set the diameter of the rope to be tested. The illumination of the rope 10 can preferably be done with artificial light sources, which allow a better contrast in the image data set. In particular, the image data acquisition device 24 Have high-power LEDs as a light source.

3a shows an image data acquisition device 24 which is designed a rope 10 in an image data record. The image data acquisition device 24 In the preferred embodiment, it comprises 4 cameras (not shown) which are in a plane perpendicular to the longitudinal direction L of the rope 10 around a rope passage opening 62 the image data acquisition device 24 are arranged. The rope 10 is through the rope passage opening 62 relative to the image data acquisition device 24 along or against the longitudinal direction L displaced. It is understood that in the case of a stationary rope and the image data acquisition device 24 can be moved. More preferably, the image data acquisition device knows 24 a rope feed measuring device 64 on which the length of the along or against the longitudinal direction L shifted rope 10 can measure or capture. In particular, a measuring wheel 64 as preferred Seilvorschubmeßeinrichtung 64 be provided, which in frictional engagement with the rope 10 stands and therefore by the advance of the rope 10 is turned. With the measuring wheel 64 For example, a pulse generator can be connected, so that a rotation of the measuring wheel 64 generates a recordable pulse by a predetermined angle. The number of pulses can be during the feed of the rope 10 registered or counted and assigned to individual images of the image data set. Advantageously, it is by means of Seilvorsschubmeßeinrichtung 64 or the measuring wheel 64 possible, captured image data or a part of the image data set a geometric position along the rope 10 assigned.

4 shows a step for detecting rope-specific setpoints by means of a data input mask 28 , The data entry mask 28 includes, for example, the stroke length S ₀ specified by the manufacturer as well as the desired value of the diameter D ₀ . The actual values of the diameter D _m and the lay length S _m determined using a representative cable section can be entered and used as a comparison value for determining deviations with regard to the local diameter and the lay length.

5 shows a further step for detecting rope-specific target values by means of a cable section 30 contained image data set. Manually or automatically, the envelopes 22a . 22b of the rope section 30 be set, with the help of the longitudinal extent L of the cable section 30 and the diameter D _m in the cable section can be determined. For example, by a user further at least two bases can be set, for example by pressing an operating element of a display device, which the cable section 30 represents, wherein the support points a straight connecting line or striking line 32 define such that the connecting line of the boundary line between two adjacent strands 12 . 12a equivalent. This step can be performed for multiple borderlines between multiple strands. By means of at least one specific connecting or striking lines 32 , which are parallel to the longitudinal direction K of the strand 12 runs, the impact angle α relative to the longitudinal direction or longitudinal extent L of the cable section 30 be determined. Next can be a reference point 38 be determined, which is located substantially in the middle between two headlines 32 is arranged, and as a reference for the middle of the strand 12 can be used, for example, the bases for the setpoints of the individual wires 16 . 16a relative to the sem reference point, ie relative to the strand 12 to determine.

Accordingly, further support points can be determined, which are a substantially straight connecting line or wire boundary line 34 define such that the connecting line of the boundary line between two adjacent wires 16 . 16a equivalent. Further, support points can be defined, preferably by the user, which have a substantially straight connection line or wire line 36 define such that the connecting line substantially the center line of a wire 16a equivalent. By means of the wire boundary line 34 and / or the wire line 36 can the wire angle β relative to the longitudinal direction or longitudinal extent L of the cable section 30 be determined.

6 shows the setpoints, as with respect to the 5 have been determined.

7 shows the automatic determination of the local pictorial diameter D _{m of} the rope in the image data set. The determination of the local diameter D _m can preferably take place by means of edge detection, preferably based on a smoothed image data set. For example, the determination of the local diameter D _m based on a diameter correlation (shown in FIG 7 as a curve with reference numerals 40 ), a calculated entropy (shown in 7 as a curve with reference numerals 42 ) and / or edge detection (shown in FIG 7 as a curve with reference numerals 44 ) be performed. The resulting local diameter D _m can, as in 7a shown (shown as a curve with reference numerals 45 ), are applied against the rope length.

8th shows the automatic determination of the beat length in the image data set, ie a localized beat length S _m . The determination of the lay length S _m on the evaluation of the brightness values of the image data set along the longitudinal direction or longitudinal extent of the cable or of the cable section can preferably take place (shown in FIG 7 as a curve with reference numerals 46 ). In order to eliminate the effect of linear displacements, a transformation into the Fourier space can be carried out, wherein the spatial wavenumbers are no longer localized and a displacement of the cable along the longitudinal direction L does not affect the result. To determine the lay length, the number of strands, for example, 6, and the previously detected actual strike length (see 4 ) be used. The lay length S _m can be determined by multiplying the number of strands and strand width.

The position of boundary lines of two adjacent strands, ie the break line 32 , can be determined by a cross-correlation with a known strand structure, as it can be detected, for example, in determining the setpoints. The boundary lines are usually characterized by well-defined areas with low brightness values, since there is usually a strong shadow between two strands occurs.

The specific local lay length S _m can, as in 8a shown (shown as a curve with reference numerals 48 ), are applied against the rope length. In addition to the lay length S _m , the center of the strand can also be determined as a reference point for further steps of the test method.

9 schematically shows the automatic detection of wire distortions in an image data set. In a preferred embodiment of the test method, the extent to which the actual longitudinal extent J _{m of} a wire is determined with the aid of the geometry quality value G _G 16 deviates from the desired value of the pictorial longitudinal extent J ₀ . In the illustrated embodiment of the method, the desired value of the longitudinal extension J _{0 is} relative to the longitudinal extent K _{m of} the strand 12 defined, which are parallel to the hitting line 32 runs. The geometry quality value G _G is preferably defined as an adaptation error with respect to an adaptation by means of a straight line. As in 9 shown is the wire 16 at a recycling center 53 only poorly adaptable by a straight line. Therefore, a wire warp can be detected at this point. Alternatively or additionally, a certain variation of the longitudinal extent between adjacent wires 16 . 16a indicate a fault or rejection of two adjacent wires.

10 schematically shows the automatic detection of wire breaks in an image data set. In a preferred embodiment of the test method is how to 8th described on the basis of the detected strand boundaries and the headlines 32 the strand center 38 calculated. At the strand center 38 become the previously determined set values for the longitudinal extensions J _{0 of} the wires 16 aligned, which is part of the strand 12 are. By means of an adaptation, in particular an iterative adaptation, the actual longitudinal extensions in the wires become 16 certainly. Set points which represent a center line of a wire are adjusted in such a way that these center lines or wire lines follow as bright points as possible of the image data set. Setpoint values which represent a borderline between two adjacent wires are adapted in such a way that these boundary lines follow as dark a spot as possible of the image data set. As a further boundary condition of the adaptation can be provided that adjacent bases of wires and boundary lines between wires displace each other, ie assume a maximum distance from each other. To perform the adjustment is For example, the optimization of a multi-dimensional cost function necessary.

For every recognizable or sufficiently dissolvable wire 16 can now along an associated matched continuous line 50 showing the longitudinal extent J _{m of} the wire 16 represents, the brightness value of the image are determined, so that from a brightness distribution function 52 along the line 50 results. In the in 9 example shown results in a break point 54 of the wire 16 to a variation of the brightness distribution function 52 so that the brightness distribution function 52 in an interval 56 has a reduced local mean.

Changed local mean values of the brightness distribution function 52 can be evaluated automatically by means of a quality of continuity G _S , so that brightness value change along a line 50 (light-dark, dark-light) leads to an exceeding of the continuity quality value and thus to an error detection.

It will be understood that the method described above also applies to the boundary lines between two wires 16 is applicable and preferably used in addition.

11 shows the result of the test procedure. In accordance with the determined quality values on the basis of the associated quality standards, which preferably each represent a yardstick for an associated cable fault, conspicuous rope sections were discriminated and with the corresponding cable position and the determined cable fault in an error log 58 summarized. The computer program which carries out the method according to the invention preferably provides a link between the elements of the error log 58 and one, in particular full-scale, pictorial representation 60 , the rope section 30 her, which the error (for example, a wire break 54 ) having. Advantageously, a human examiner can use the error log to visually check or verify all potential rope faults on the basis of the pictorial representation without actually having the rope section in front of his eyes. Advantageously, the test method can be performed remotely from the place of use of the rope. Further advantageously, the visual verification or verification on the automatically discriminated cable sections 30 be limited so that about 90 percent of a rope requires no inspection by a human examiner. More preferably, the test method and the evaluation of the discriminated cable errors can be done automatically.

10

rope or stranded rope

12 12a

braid

14

rope core

16

wire

18

strand core

20a, 20b

Litzenseilkonturlinie

22a, 22b

Enveloping the Litzenseilkonturlinie

24

Image data acquisition device

26a-26d

camera

28

Data entry screen

30

cable section

32

connecting line or headline

34

connecting line or wire boundary line

36

connecting line or wire line

40

Diameter correlation function

42

entropy

44

Edge detection function

45

Function of the local diameter D _m

46

function the brightness values along the longitudinal direction L

48

Function of local lay length S _m

50

adapted line

52

Brightness distribution function

53

fault location

54

breaking point

56

interval

58

error log

60

pictorial presentation

62

Rope through opening

64

Seilvorschubmeßeinrichtung

D, D ₀ , D _m

diameter

G _D , G _S , G _G

quality value

J, J ₀ , J _m

longitudinal direction

K, K ₀ , K _m

longitudinal direction

L

longitudinal direction

S, S ₀ , S _m

lay length

α

impact angle

β

wire angle

β

Wire strands angle

Claims (11)

System for optically testing a rope ( 10 ) comprising: - at least one image data acquisition device ( 24 ), which is designed at least a section ( 30 ) of the rope ( 10 ) optically detect; A nominal value memory unit which is designed nominal values of the longitudinal extent K _{0 of} the heddles ( 12 . 12a ) and / or the longitudinal extent J _{0 of} the wires ( 16 . 16a ), in particular relative to the longitudinal extent K _{0 of} the strands ( 12 . 12a ) to provide a discrimination unit; An image data evaluation unit which is designed to have a longitudinal extent K _{m of} the strands ( 12 . 12a ) in the section ( 30 ) of the rope ( 10 ) and / or the longitudinal extent J _{m of} the wires ( 16 . 16a ) by doing covered section ( 30 ) of the rope ( 10 ), in particular relative to the determined longitudinal extent K _{m of} the strands ( 12 . 12a ) to determine; The discriminating unit which is designed, at least one quality value by means of a quality standard as a function of the determined longitudinal extent J _{m of} the wires ( 16 . 16a ) and the set values of the longitudinal extent J _{m of} the wires ( 16 . 16a ) and or; at least one quality value by means of a quality standard as a function of the determined longitudinal extent K _{m of} the strands ( 12 . 162 ) and the nominal values of the longitudinal extent K _{0 of} the strands ( 12 . 12a ) to determine; - the pictorial positions within the image data set of the rope ( 10 ) at which at least one quality value exceeds or falls below a predetermined assigned quality limit value; and - an output unit. A system according to claim 1, wherein said setpoint storage unit has setpoint values of the pictorial longitudinal extent of the representation of strands ( 12 . 12a ) relative to the pictorial longitudinal extension of the rope ( 10 ) in the image data set, wherein the image data evaluation unit is designed, the pictorial longitudinal extent of the strands ( 12 . 12a ) in the image data set, and wherein the discrimination unit is designed to produce at least one impact quality value (G _S ) by means of a impact quality standard as a function of the determined pictorial longitudinal extent of the strands (US Pat. 16 . 16a ) and the nominal values of the pictorial longitudinal extent of the strands ( 16 . 16a ). A system according to claim 2, wherein said setpoint storage unit has set values of the pictorial longitudinal extent J _{0 of} the representation of wires ( 16 . 16a ) relative to the pictorial longitudinal extent of the strands ( 12 . 12a ) in the image data set, wherein the image data evaluation unit is designed, the pictorial longitudinal extent J _{0 of} the wires ( 16 . 16a ) relative to the particular longitudinal extent of the strands ( 12 . 12a ) in the image data set. System according to one of the preceding claims, wherein the discriminating unit is adapted to determine a geometric quality value (G _G ) which is determined by means of a geometry gum standard as a function of a geometric distance between the determined pictorial longitudinal extent J _{m of} the wires ( 16 . 16a ) and the set values of the pictorial longitudinal extent J _{0 of} the wires ( 16 . 16a ) or - as a function of a geometric distance between the specific pictorial longitudinal extents of at least two adjacent wires ( 16 . 16a ) is determined. System according to one of the preceding claims, wherein the image evaluation unit and / or the discriminating unit are designed to provide a brightness distribution function ( 52 ) along the particular pictorial longitudinal extent of the wires ( 16 . 16a ), wherein the at least one specific quality value comprises a continuity quality value (G _S ) which is characterized by a continuity quality function as a function of the brightness distribution function, the first derivative of the brightness distribution function and / or the second derivative of the brightness distribution function and / or its nth order moments n = 0, 1, 2 is determined. System according to one of the preceding claims, wherein the setpoint memory unit is designed to provide setpoint values of the local diameter D _m , wherein the image evaluation unit and / or the discrimination unit are designed to match the local pictorial diameter D _{m of} the rope ( 10 ) in the image data set and wherein the discrimination unit is adapted to determine a diameter quality value (G _D ) by means of a diameter quality standard as a function of the determined image diameter D _m and the target values of the local diameter D. A system as claimed in any one of the preceding claims, wherein the system comprises input means for allowing a user to: - select an image data set, - determine at least two interpolation points and a connecting line defined by the interpolation points such that the connecting line substantially coincides with - a boundary line between two adjacent strands ( 12 . 12a ) or - a borderline between two adjacent wires ( 16 . 16a ) or - a centerline of a strand ( 12 . 12a ) or - a center line of one of the wires ( 16 . 16a ); and - to store the interpolation points on a storage medium. System according to one of the preceding claims, wherein the discriminating unit is designed, the assignment of the quality value to the associated discriminated spatial positions along the rope ( 10 ). A system according to claim 8, wherein the system comprises a cable feed measuring device ( 64 ). System according to one of the preceding claims, comprising a cable assessment unit which is designed to adjust the pictorial or spatial positions discriminated by the discrimination unit along the cable ( 10 ) assign a valuation characteristic. A computer program product comprising computer readable instructions, the instructions comprising a method according to any one of the preceding Perform claims when loaded and run on a suitable computer system.