Sliding transport of rolled product with adaption of friction A starting point of the present invention is a control method for a pinch roll for delivering rolled products,

- wherein the pinch roll delivers a respective rolled

product,

- wherein a control device for the pinch roll opens the pinch roll at a respective trigger time and at a respective transport speed of the respective rolled product.

A further starting point of the present invention is a computer program comprising program code which is executable by a control device for a pinch roll wherein executing the program code by the control device effects the implementation of such a control method.

A further starting point of the present invention is a control device for a pinch roll wherein the control device is programmed with such a computer program so that the control device controls the pinch roll according to such a control method . A further starting point of the present invention is a transport device for delivering a rolled product,

- wherein the transport device comprises an openable pinch roll for transporting rolled products,

- wherein the transport device comprises a control device of the above-mentioned type.

After rolling a product - especially a bar-shaped product - the rolled product in many cases is delivered by means of a pinch roll to a cooling bed where it cools down. During cooling and after cooling the rolled product is transported in a direction rectangular to the previous direction of transport. Then the rolled product is processed further. To enable an easy further processing, the rolled products should be positioned on the cooling bed in a defined position.

In the prior art, an operator determines the correct trigger time and/or the correct transport speed. Especially, the operator issues an opening command to the control device. In response to the opening command, the control device opens the pinch roll. The method of the prior art reguires an

experienced operator to achieve good results.

It is an object of the present invention to position the rolled products in a defined position on said cooling bed in a simple, efficient, and reliable manner. The object is achieved by a control method having the features of claim 1. Preferred embodiments of the control method are claimed in claims 2 to 6.

According to the present invention, a control method of the above-mentioned type is augmented by the steps

- that said control device determines said respective trigger time and/or said respective transport speed using a model in dependency on a coefficient of friction used by the model,

- that, after opening said pinch roll, a measuring device detects iteratively a position or a derivation in time of the position of the respective rolled product,

- that said detected positions or said detected derivations in time of the position are provided to said control device, and

- that said control device in dependency on said detected positions or said detected derivations in time of the position of the respective rolled product updates said coefficient of friction and uses said updated coefficient of friction for determining the respective trigger time and/or the respective transport speed for the next rolled product delivered by the pinch roll. Thus, the control device determines in dependency of the coefficient of friction by a model the respective trigger time and/or the respective transport speed. According to the invention, further, in dependency on said detected positions or said detected derivations in time of the position of the respective rolled product the coefficient of friction is updated. Therefore it is possible not only to adapt the sliding movement of the rolled product. It is further possible to adapt the model to the real behaviour of the rolled product. The model is learning the actual behaviour of the rolled product .

The rolled products may be plate. Preferably, however, the rolled products are bar-shaped. They may have a profile, for example a T-profile, an I-profile, a double-T-profile , a X- profile, an U-profile, and so on.

In a preferred embodiment of the control method, said measuring device detects said positions or said derivations in time of the position without contacting the respective rolled product. Especially, said measuring device may be a optical measuring device, for example a laser gauge meter.

In a further preferred embodiment, the measuring device or an additional measuring device detects a respective final position of the respective rolled product. In this case, the respective final position is provided to the control device, and the control device updates the coefficient of friction in further dependency on the respective final position of the respective rolled product.

The object is further achieved by a computer program having the features of claim 7. According to the invention,

executing the computer program effects the implementation of a control method of the present invention.

The object is further achieved by a control device having the features of claim 8. According to the invention, the control device is programmed with a computer program according to the present invention so that the control device controls the pinch roll according to a control method of the present invention .

The object is further achieved by a transport device having the features of claim 9. According to the invention, the transport device comprises a measuring device for after opening said pinch roll iteratively detecting a position or a derivation in time of position of said rolled product, and the control device being adapted to control the pinch roll according to a control method of the present invention.

The features, properties and advantages of the present invention will be understood more easily by the following description of preferred embodiments which are explained in combination with the drawings. In the attached drawings:

FIG 1 shows a transport device,

FIG 2 shows a pinch roll in a closed state,

FIG 3 shows the pinch roll of FIG 2 in an opened state,

FIG 4 shows a seguence of steps, and

FIG 5 shows another seguence of steps. As shown in FIG 1, a transport device for transporting rolled products 1 comprises a pinch roll 2. The rolled products 1 may be rod-shaped, especially. By means of the pinch roll 2 a respective of the rolled products 1 is delivered. The pinch roll 2 may- in accordance to a control signal from a control device 3 - be opened and closed. FIG 2 shows the pinch roll 2 in its closed state. In this state, rolls of pinch roll 2 contact the respective rolled product 1 under pressure. The respective rolled product 1 is therefore delivered according to the circumferential speed of the rolls of the pinch roll 2. FIG 3 shows the pinch roll 2 in its opened state. In this state, the rolls of the pinch roll 2 do not contact the respective rolled product 1. The movement of the respective rolled product 1 therefore is independent of the circumferential speed of the rolls of the pinch roll 2.

The control device 3 is programmed by a computer program 4. The computer program 4 may be provided to the control device 3 for example via a data carrier 5 on which the computer program 4 is stored in machine-readable form, for example in electronic form. The computer program 4 comprises machine code 6 executable by the control device 3. By executing the machine code 6, the control device 3 operates the pinch roll according to a control method which will be explained in detail below.

The respective rolled product 1 shall be delivered by means of the pinch roll 2 in a way that it stops on a surface 7 at a predetermined position. The surface 7 may be a cooling bed, for example. The predetermined position may be characterised for example by the fact that after stopping a head end of the respective rolled product 1 is positioned at a predetermined forward final position xl . Alternatively, the predetermined position may be characterised for example by the fact that after stopping a tail end of the respective rolled product 1 is positioned at a predetermined rear final position x2.

Other embodiments are possible.

For achieving the respective positioning, the respective rolled product 1 is delivered by the pinch roll 2. At a respective trigger time tO the control device 3 opens the pinch roll 2. At the trigger time tO the respective rolled product 1 has a respective transport speed vO . Due to its inertia the respective rolled product 1 slides upon the surface 7. The speed v of the respective rolled product 1, however, decreases due to friction between the respective rolled product 1 and the surface 7. After some time and after moving a certain distance, the rolled product 1 therefore stops . As shown in FIG 4, the control device 3 determines in a step SI the respective trigger time tO and the respective

transport speed vO in dependency on a coefficient R of friction in a coordinated manner. Coordination is such that - assuming the coefficient R of friction is correct - the respective rolled product 1 is positioned on the surface 7 as desired. Especially, the control device 3 determines by using a model M in dependency on the trigger time tO and the transport speed vO a position at which the respective rolled product 1 stops. For example, the control device 3 may determine by using the model M an calculated final position at which a head end 8 of the respective rolled product 1 or a tail end 9 of the respective rolled product 1 stops. Model M models the sliding of the respective rolled product 1 on the surface 7. It uses (inter alia) the coefficient R of

friction .

It is possible that the transport speed vO is predetermined and not varied. In that case, in step SI exclusively the trigger time tO is determined. Alternatively, it is possible that the trigger time tO is predetermined and not varied. In that case, in step SI exclusively the transport speed vO is determined. Alternatively, it is possible that both the trigger time tO and the transport speed vO are varied. In that case, in step SI both values tO, vO are determined.

According to the determination in step SI the control device 3 controls in a step S2 the pinch roll 2 such that the circumferential speed of the rolls of the pinch roll 2 corresponds to the transport speed vO . In a step S3, the control device 3 checks whether the trigger time tO is reached. When the trigger time tO is reached, the control device 3 in a step S4 opens the pinch roll 2. As shown in FIG 1, the transport device further comprises a measuring device 10. By means of the measuring device 10 iteratively - for example each 10 ms - the position p of the respective rolled product 1 is detected. Detection occurs at least after opening of pinch roll 2. The measuring device 10 provides the detected positions p to the control device 3. The detected positions p are input into the control device 3 in a step S5. Alternatively or additionally to a detection of positions p there may be iteratively a detecting of a derivation in time of the position p, including providing the detected derivation to the control device 3. For example, by means of the measuring device 10 there may be detected directly the instantaneous speed v (= first derivation in time of position p) . Alternatively, there may be detected directly the acceleration (= second derivation in time of position p) .

The measuring device 10 may be as reguired. Preferably, the measuring device 10 is construed in a manner that it is able to detect the positions p or the derivations in time of the position p without contacting the respective rolled product 1. The measuring device 10 may be an optical measuring device, for example. Examples of such measuring devices are an optical camera, an infrared camera, a CCD-camera and so on. Especially preferred is that the measuring device 10 is a laser gauge meter. The measuring device 10 may work according to the Doppler-effect . In a step S6, the control device 3 updates the coefficient R of friction. Updating is done in dependency on the detected positions p or the detected derivations in time of position p of the respective rolled product 1. After updating said coefficient R of friction, the control device 3 continues with step SI. When executing step SI this time, however, of course not the rolled product 1 considered up to now is delivered. Instead, the next rolled product 1 is delivered. Due to the actualisation of the coefficient R of friction, the control device 3 uses for determining of trigger time tO and/or transport speed vO of the next delivered rolled product 1 the updated coefficient R of friction, however. As shown in FIG 1, in a preferred embodiment additionally a final position xl, x2 at which the respective rolled product 1 stops is detected. Detection may be done by the measuring device 10. Alternatively, detection may be done by means of an additional measuring device 11. The additional measuring device 11 may be - in anology to measuring device 10 - such that it detects the respective final position xl, x2 without contacting the respective rolled product 1. For example, the additional measuring device 11 may be - in anology to measuring device 10 - and optical measuring device. The disclosure given above with respect to the measuring device 10 applies also to the additional measuring device 11.

In case the final position xl, x2 is detected, the method shown in FIG 4 is modified as shown in FIG 5.

FIG 5 comprises steps SI to S5 of FIG 4. Steps SI to S5 were explained already. Further, as shown in FIG 5, there is an additional step S7. In step S7, the respective final position xl, x2 is provided to the control device 3. Further, the step S6 is replaced by a step S8. In step S8, the control device 3 updates - in anology to step S6 of FIG 4 - the coefficient R of friction. In contrast to step S6, the control device 3 in step S8 additionally to the detected positions p or the detected derivations in time of position p also takes in account the respective final position xl, x2 of the

respective rolled product 1.

In short, therefore, the present invention concerns the following subject matter:

A pinch roll 2 delivers a respective rolled product 1. A control device 3 for the pinch roll 2 opens the pinch roll 2 at a respective trigger time tO and at a respective transport speed vO of the respective rolled product 1. The control device 3 determines said respective trigger time tO and/or said respective transport speed vO using a model M in dependency on a coefficient R of friction used by the model M. After opening said pinch roll 2, a measuring device 10 detects iteratively a position p or a derivation in time of the position p of the respective rolled product 1. The detected positions p or said detected derivations in time of the position p are provided to said control device 3. The control device 3 in dependency on said detected positions p or said detected derivations in time of the position p of the respective rolled product 1 updates said coefficient R of friction and uses said updated coefficient R of friction for determining the respective trigger time tO and/or the respective transport speed vO for the next rolled product 1 delivered by the the pinch roll (2) .

The present invention has many advantages. Most importantly, automatic determination of trigger time tO and/or transport speed vO results in a reproducible, deterministic behaviour of rolled products 1. Further, due to updating the

coefficient R of friction positioning of rolled products 1 may be improved continuously.

The present invention was explained above by a plurality of preferred embodiments. The present invention is, however, not restricted to these embodiments. Variations can be found easily by the person skilled in the art without deviating from the scope of the present invention which shall be defined solely by the attached claims.