EP2010714B1 - Levelling device for a paver and method of controlling the cutting depth or cutting inclination in a road-making machine - Google Patents

Description

The invention relates to a leveling device according to the preamble of claim 1 and a method according to the preamble of claim 10.

It is already known in road milling machines to integrate a leveling device, with the help of which it is to be ensured that a flat milling surface can be produced.

The milling depth control system is designed so that different sensors can be connected. For example, u.a. Draw wire sensors, ultrasonic sensors and tilt sensors are used.

A draw wire sensor is attached to the side plates (edge protection) next to the milling drum and thus scans the reference surface, here the road surface, very accurately. The ultrasonic sensor works without contact and is therefore not subject to any mechanical wear. It can be used in a variety of ways as it can be attached to the machine at various positions.

If a defined bank angle is to be generated, it is also possible to use a tilt sensor which is integrated in the road milling machine.

The known milling depth control system can have two independent control circuits. In each control loop, a controller is provided, to which the sensors can be connected via plug connections. For example, either two height sensors or a height sensor are provided in combination with a tilt sensor.

The document EP1154075 discloses a leveling device according to the preamble of claim 1 and a method according to the preamble of claim 10.

A disadvantage of the prior art that the application-related frequent change between the many different sensors not without interrupting the milling operation and not without negative influences on the work remains. Since only one controller or only one display and setting device for setpoints and actual values per controller exists, the automatic mode of the control must first be left to change the current sensor. Then, the new sensor can be selected and the desired setpoint can be set, before it can be changed back to the automatic mode of control. If, during the change of the sensor, the road milling machine would continue to be routed, then errors in the work result can arise because no control takes place during this time. Therefore, the machine must be stopped for a change of the sensor, resulting in a considerable loss of time. Even if the road milling machine is stopped when changing the sensor, there is an impairment of the work result, because the milling drum free-cutting when standing. This is an undesirable effect, especially in fine milling.

The invention is therefore based on the object to provide a leveling device and a method for controlling the cutting depth and / or the Fräsneigung, in which a change of the sensors without interrupting the milling operation is possible.

To achieve this object, the features of claims 1 and 10 serve.

The invention advantageously provides that the display and adjustment device of the leveling device, in addition to a display and setting unit provided for the at least one currently used sensor, has an additional Display and adjustment unit for a against the currently used sensor to be replaced and selectable sensor. The provision of a further display and adjustment unit has the advantage that, during operation, the new sensor to be exchanged for a currently used sensor can be prepared for its actual and setpoint values for the changeover time. At the time of switching, therefore, the sensor can be changed without the currently valid manipulated variable being changed. The leveling device has a device for switching sensors, which without interrupting the milling operation when triggering a Umschalbefehls switching the leveling of the at least one current sensor on at least one preselected other sensor without sudden change of the current control value for the adjustment of the milling depth and / or for adjusting the inclination of the milling drum.

The switching device allows with the display and adjustment a pre-selection of the other sensor and the pre-adjustment of operating parameters (setpoints and actual values) of the other pre-selected sensor.

In this way, a driver can already prepare the switching of the sensors during the milling operation, so that the switching of the sensors at the touch of a button without loss of time and without interrupting the milling operation is possible.

For this purpose, the leveling device has a display and setting device which can display and change the data of the current sensor and the data of the pre-selected sensor. With the help of the switching device can be switched without affecting the work result in the milling operation of the current sensor to the pre-selected sensor.

In one embodiment of the invention it is provided that the currently measured actual value for the milling depth and / or for the inclination of the milling drum of the at least one preselected other sensor at the latest at the time of switching to the same, last measured actual value for the milling depth and / or is settable for the inclination of the previously used sensor.

It is thus possible, when changing the sensor, to take over the actual value of the last used sensor, so that the control value for the adjustment of the milling depth and / or for adjusting the inclination of the milling drum is not changed due to the change and the flatness of the milled Road surface is not affected by the change of the sensor.

According to an alternative embodiment, it is provided that the setpoint value for the milling depth and / or for the inclination of the milling drum can be set at the latest at the time of switching to the currently measured actual value of the milling depth of the at least one pre-selected sensor.

By equating the setpoint value with the currently measured actual value of the pre-selected sensor which replaces the previous sensor, it is ensured that no change occurs in the setpoint for setting the milling depth and / or the inclination at the time of the switchover.

In a third exemplary embodiment, it is provided that in the case of a deviation of the measured actual values of the selected other sensor from the previously used sensor, the setting value for setting the milling depth and / or setting the inclination can be changed with a presettable transition function.

According to a further alternative, it is accordingly provided that in the event that there is a change in the current control value due to the switching of the sensors, this change follows a presettable transition function starting from a control value 0. This ensures that the change in the control value does not occur abruptly, so that the flatness of the milled road surface is not affected and the adaptation to the resulting due to the switching control value over a longer distance, for. over 10m or more.

Preferably, it is provided that the leveling device has two regulators whose sensors are arranged parallel to the axis of rotation of the milling drum with a lateral distance from each other, and preferably independently of one another on the left and right sides of the machine to control the milling depth.

According to the method for controlling the cutting depth or the milling tendency of the milling drum of a road construction machine by detecting the current actual value of the milling depth and / or the inclination of the milling drum in relation to a reference surface with at least one interchangeable or switchable sensor, wherein a milling depth control and / or a tilt control for the milling drum is executed as a function of predetermined setpoint values and currently measured actual values in milling operation by output of a control value for achieving or maintaining the setpoint, it is provided that when changing a currently used sensor against a pre-selected other sensor, the control of the milling depth and / or the inclination is performed without interrupting the milling operation by the set and actual values of the sensor before switching over using an additional display and adjustment unit are set such that the current control value for the adjustment of the milling iefe and / or is not changed abruptly for the adjustment of the inclination of the milling drum.

When a switching command for switching sensors is triggered, the control is executed without interrupting the milling operation and without sudden change of the current control value for setting the milling depth and / or for adjusting the inclination of the milling drum.

As a reference surface, the road surface or a defined horizontal plane, for example given by a laser, or any other freely definable preselected surface can be used, which may have a different slope or slope (positive or negative) in the course of the road surface.

In the following, embodiments of the invention will be explained in more detail with reference to the drawings:

Fig. 1

eine Straßenbaumaschine,

Fig. 2

eine Nivelliereinrichtung,

Fig. 3

eine Anzeige- und Einstelleinrichtung,

Fig. 4

einen Abgleich der Istwerte verschiedener Sensoren bei der Umschaltung,

Fig. 5

einen Abgleich des Sollwertes auf den Istwert eines neuen Sensors bei der Umschaltung,

Fig. 6a Fig. 6b

den Wechsel von einer Frästiefenregelung zu einer Fräsneigungs-regelung

Fig. 7a bis 7c

den Umschaltvorgang mit Sollwertabgleich, und

Fig. 8a bis 8d

eine Umschaltung mit Istwert- und Sollwertabgleich.

Show it:

Fig. 1

a road construction machine,

Fig. 2

a leveling device,

Fig. 3

a display and adjustment device,

Fig. 4

an adjustment of the actual values of different sensors during the changeover,

Fig. 5

an adjustment of the setpoint value to the actual value of a new sensor during the switchover,

Fig. 6a Fig. 6b

the change from a milling depth control to a milling tilt control

Fig. 7a to 7c

the switching process with setpoint adjustment, and

Fig. 8a to 8d

a changeover with actual value and setpoint adjustment.

Fig. 1 shows a road machine 1 for processing road surfaces with a height-adjustable milling depth with respect to the milling drum 3. The front suspension is based for example on the road surface 12, which can serve as a reference surface for a Fries depth or inclination control. For this purpose, the road machine 1 has a leveling device 4, with at least one controller 6a, 6c, which receives setpoint values for the milling depth and / or the inclination of the milling drum 2. Interchangeable sensors A, B, C can be connected to the regulators 6a, 6c of the leveling device 4. The sensors A, B, C are used for detecting the current actual value of the milling depth and / or the inclination of the milling drum 3 in relation to a reference surface, from the road surface 12, a predetermined horizontal plane or from a freely definable, eg mathematically predetermined plane or area can exist.

The at least one controller 6a, 6c carries out a milling depth control and / or a tilt control for the milling drum 3 as a function of predetermined setpoint values and the currently measured actual values of the at least one sensor A, B, C, wherein a control value for achieving or maintaining the setpoint value in Milling operation is issued. The leveling device 4, as shown Fig. 2 shows, a display and adjustment, which is divided into three nearly identical display and adjustment units 2a, 2b, 2c. The display and setting device 2 is used to set operating parameters for the sensors A, B, C. Set and actual values of the sensors A, B, C can be set in each display and setting unit 2a, 2b, 2c. The display and adjustment unit 2a and 2c right and left are each connected to a controller 6a, 6c, which can be activated with an automatic button for each automatic control. During switching, the controllers remain in automatic mode. The resulting from the difference of the setpoint and actual value control value of the controller 6a, 6c is displayed qualitatively with arrows 14, wherein the display of the vertical travel speed of the machine proportionally, so can also display quantitatively. The predefined setpoint and actual values of the middle display and adjustment unit 2b, which is coupled to a sensor B which is to be exchanged and selectable against the currently used sensor A or C, can be compared with the desired and actual values of the sensor A or with a changeover device 10a or 10b C to be exchanged for a selectable other sensor B.

The embodiment shows a version in which in each case a controller 6a, 6c is provided for one side of the road construction machine 1. It is understood that the display and adjustment device 2 may also have only two display and adjustment units, if only one controller is present, with one sensor being exchanged for another selectable sensor.

It is therefore always provided a display and adjustment more than the number of sensors in operation.

Fig. 2 shows the connection of the sensors A, B, C to the leveling device 4 with two regulators 6a, 6c, the leveling device having a display and adjustment device 2 with three display and adjustment units 2a, 2b, 2c,

Fig. 3 shows an embodiment of the display and adjustment device 2, wherein for each display and adjustment unit 2a, 2b, 2c adjustment buttons 16 (up and down) for setting setpoints, as well as adjustment buttons 18 (up and down) for the adjustment of measured actual values available are.

On the displays 20 of the display and adjustment units 2a, 2b, 2c, the currently set desired values and the currently measured actual values of the sensors A, B, C are displayed. On the displays 20, the direction of a possibly set inclination of the milling drum can be displayed. Furthermore, units are e.g. in inches or cm or percentages in% referring to the displayed value.

A selection of sensors is displayed at the lower end 22 of the display 20 so that a vehicle driver can determine from the current display which type of sensor is currently displayed on the display and setting unit 2a, 2b, 2c. The symbols represent from left to right a cable pull sensor, a tilt sensor, an ultrasonic sensor, a multiplex sensor, a total station and a laser for specifying the reference surface.

Above the displays 20, one button is provided for each of the automatic mode and the setting mode for setting the controller parameters. On the display and adjustment device 2, a horn 24, as well as buttons 26 may be provided for adjusting the height of the chassis. Two memory buttons M1, M2 are provided below the display 20 for storing setpoint values on the middle display and adjustment unit 2b.

In the FIGS. 4 to 6 Several options are explained in which way a sudden change of the current control value can be avoided.

In the embodiment of the Fig. 4 an equation of the measured actual value - of the preselected sensor B with the last measured current takes place Actual value of the previously used sensor A at the time of switching.

In Fig. 5 the predetermined setpoint is adapted to the currently measured actual value of the preselected sensor B, so that no change in the control value occurs in this case.

In the case of a deviation of the measured actual values of the previously used sensor A from the preselected new sensor B, as an alternative to the exemplary embodiments of FIGS 4 and 5 the manipulated variable is also transferred to the manipulated variable resulting from the differences of the actual values with the aid of a transition function. Consequently, there is a time transition, whereby no sudden change of the control value can occur.

The FIGS. 6a and 6b show a changeover in the regulated state. Fig. 6a shows the initial situation in which the display and setting unit 2c associated with the controller 6c is to be switched over from the operating mode milling depth (setpoint 10.0 cm) to the milling tilt (setpoint 2%) operating mode. The changeover takes place in the regulated state. This means that the respective actual value on both sides of the machine corresponds to the setpoint and therefore the control value is 0 on both sides. The adjusted state is indicated by the display and setting means 14a, 14c by a horizontal bar. Upon actuation of the shift key 10b of the switching device 10 will be like Fig. 6b can be seen, the preselected setpoint and actual values of the display and adjustment unit 2b on the display unit 2c exchanged and used in the continued automatic operation of a mixed milling depth and Fräsneigungsregelung based.

The FIGS. 7a to 7c show the changeover with setpoint adjustment.

In this example, the setting values on both sides of the machine are not equal to 0. The display and setting unit 2c of the controller 6c is switched over from milling depth control to milling tilt control. The target value of the inclination is manually in Fig. 7b adjusted by pressing the keys 16, so that no sudden change in the control value takes place. The example assumes that the manipulated variable is proportional to the control difference (P controller) and that the proportionality factor for milling depth and milling inclination is numerically the same. The control difference is 0.3 cm for the milling depth (display and setting unit 2c in Fig. 7a ) for the milling inclination 0.6% (display and adjustment unit 2b in Fig. 7a ), so that the manipulated variable would double in value after switching. In order to adjust the control difference, the target value of the inclination is reduced to 2.0, which gives a numerically equal control difference. This can be done manually via the button 16 "decrease setpoint" or automatically, eg via the key combination 16, 18 "Increase actual value and reduce setpoint value" ( Fig. 7b ).

By the operation of the shift key 10b in the illustration according to Fig. 7c the setpoint and actual value of the milling inclination is adopted, as in Fig. 7c indicated by arrows. The manipulated variable remains unchanged.

In another embodiment, not shown, an automatic setpoint adjustment can be provided. In such an embodiment, the setpoint change from the aforementioned embodiment of the FIGS. 7a to 7c automatically executed when the shift key 10b (or 10a) is operated in the automatic mode. The first step of manually changing the values in the middle display and adjustment unit 2b (FIG. Fig. 7 ) can then be omitted because this is done automatically.

Another variant, not shown, is to change the manipulated variable with a deviation of the actual values with the aid of a preset transition function, starting from the current position value.

The FIGS. 8a and 8d show an embodiment with actual value and setpoint adjustment.

In the Fig. 8a The initial situation shown with respect to the regulator 6c on the right side indicates the values of a milling depth sensor C, eg an edge protection cable pull sensor, while the middle display and adjustment unit 2b indicates the values of a milling depth sensor B, eg an ultrasonic sensor with scanning point in front of the milling drum.

The milling depth sensor C is to be replaced by the milling depth sensor B, wherein the setpoint and actual values of the two sensors B, C do not match. However, the current control value is equal to 0, as can be seen from the display device 14a, 14c.

Since the sensor B is adjusted differently, its actual value does not match the actual value of the sensor C. It can be adjusted manually or automatically with the actual value setting keys 18, e.g. be held by the holding of the two actual value setting keys 18 to the actual value of the sensor A equated.

The FIGS. 8c and 8d show the setpoint adjustment. Since the setpoint of the two sensors B, C refers to the depth of cut to the right, the setpoint of the sensor B should be adjusted to the setpoint of the sensor C. This can be done with setpoint adjustment buttons or automatically eg by holding the two setpoint adjustment buttons for longer.

After pressing the right-hand switching key 10b, the setpoint and actual value of the sensor B are accepted. The manipulated variable remains unchanged 0.

All exemplary embodiments indicate the setpoints and actual values of the preselected sensor B to be exchanged for a previously used sensor C in the display and adjustment unit 2b. This makes it possible to pre-set all setting values (setpoints and actual values) of the pre-selected sensor B before the input of a switching command via the shift keys 10a or 10b and to adapt them to the previously used sensors A, C or their nominal or actual values , When the switching key 10a of the switching device 10 is actuated, the preselected sensor is exchanged with the sensor A. currently being used on the left side of the road construction machine 1.

As previously mentioned in connection with the embodiment of Fig. 7 explained, instead of the manually executed setpoint compensation and an automatic setpoint compensation can be done when the shift key 10b (or 10a) is pressed in automatic mode.

Claims (13)

1. Levelling device (4) for a height-adjustable milling drum (3) of a road construction machine (1) for the treatment of road surfaces, wherein the milling drum is vertically adjustable with respect to the milling depth and/or the slope, comprising
   at least one controller (6a, 6c) which receives saveable set values for the milling depth and/or the slope of the milling drum (3), and
   several sensors (A, B, C) for registering the current actual value of the milling depth and/or the slope of the milling drum (3) relative to a chosen reference surface,
   where the controller (6a, 6c) effects a milling depth control and/or a slope control for the milling drum (3) conditional on pre-determined set values and the currently measured actual values by returning an adjustment value for achieving or maintaining the set value for the milling depth and/or milling slope during the milling operation,
   where the levelling device (4) is provided with an indication and setting device (2) for setting operating parameters for the at least one sensor (A, B, C),
   characterized in that
   at least one sensor (B) is exchangeable or a plurality of sensors (A, B, C) is switchable,
   a switchover device (10) for the switchover of sensors (A, B, C) is provided which, upon activation of a switchover command, effects switchover of the sensors from the at least one sensor (A; C) used to register the actual value to at least one pre-selected other, previously not used sensor (B), without interruption of the milling operation,
   the switchover device (10) is provided with an indication and setting device (2) which enables a pre-selection of the other, previously not used sensor (B) and the pre-setting of operating parameters of the previously not used sensor (B),
   where, by the pre-setting of the operation parameters of the previously not used sensor (B), the current adjustment value for the setting of the milling depth and/or for the setting of the slope of the milling drum is effected without any erratic alteration.
2. Levelling device in accordance with claim 1, characterized in that the currently measured actual value for the milling depth and/or for the slope of the milling drum (3) of the at least one selected, previously not used sensor (B) can be set, latest at the time of switchover, to the same, last measured actual value for the milling depth and/or for the slope of the previously used sensor (A; C).
3. Levelling device in accordance with claim 1, characterized in that the set value for the milling depth and/or for the slope of the milling drum (3) can be set, latest at the time of switchover, to the currently measured actual value for the milling depth of the at least one pre-selected sensor (B).
4. Levelling device in accordance with claim 1, characterized in that, in case of a deviation of the measured actual values of the selected other sensor (B) from the previously used sensor (A; C), the adjustment value for the setting of the milling depth and/or the setting of the slope can be altered by means of a pre-settable transition function.
5. Levelling device in accordance with one of the claims 1 to 4, characterized in that the levelling device (4) is provided with two controllers (6a, 6c), the sensors (A, C) of which are arranged parallel to the rotating axis of the milling drum (3) at a lateral distance to one another, and which control the milling depth independently of one another on the left and right side of the machine (1).
6. Device in accordance with one of the claims 1 to 5, characterized in that the reference surface is a road surface (12).
7. Device in accordance with one of the claims 1 to 6, characterized in that the reference surface is a horizontal plane.
8. Device in accordance with one of the claims 1 to 7, characterized in that the reference surface is a freely definable pre-selected plane.
9. Road construction machine (1) for the treatment of road surfaces comprising a milling drum (3), vertically adjustable with respect to the milling depth, having a levelling device (4) according to one of claims 1 to 7.
10. Method for controlling the milling depth or milling slope of the milling drum (3) of a road construction machine (1) by registering the current actual value of the milling depth and/or the slope of the milling drum (3) relative to a reference surface using sensors (A, B, C), where a milling depth control and/or a slope control for the milling drum (3) is effected conditional on pre-determined set values and currently measured actual values during the milling operation by outputting an adjustment value for achieving or maintaining the set value,
    characterized in that
    at least one sensor (B) is exchangeable or a plurality of sensors (A, B, C) is switchable, and
    when exchanging a sensor (A, C) used to register the actual value for a pre-selected other, previously not used sensor (B), the control of the milling depth and/or the slope is effected, without interruption of the milling operation, by, prior to the switchover to the previously not used sensor (B), selecting the previously not used sensor (B) by means of an additional indication and setting unit (2b) for the previously not used sensor (B) and pre-setting the set and/or actual values for the previously not used sensor (B) displayed on the additional indication and setting unit and adjusting the these values to the set or actual values of the previously used sensor in such a fashion that the current adjustment value for the setting of the milling depth and/or for the setting of the slope of the milling drum (3) is not altered in an erratic fashion.
11. Method in accordance with claim 10, characterized in that, when switching over from the last used sensor (A; C) to the pre-selected other sensor (B), the current actual value of the other sensor (B) is set to the same, last measured actual value of the last used sensor (A; C).
12. Method in accordance with claim 10, characterized in that, when switching over from the last used sensor (A; C) to the pre-selected sensor (B), the currently pre-determined set value is set to the actual value of the other sensor (B).
13. Method in accordance with claim 10, characterized in that, when switching over from the last used sensor (A; C) to the pre-selected, previously not used sensor (B), in case of a deviation of the actual values of the selected other sensor (B) from the previously used sensor (A; C), the currently measured set value is altered by means of a pre-settable transition function starting from the current adjustment value at the time of switchover to the adjustment value resulting on account of the difference in the actual values.

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