Road paver with control unit for determining the weight and/or the center of gravity and/or the width of the screed and corresponding method

{
  "publication_number": "US10260205B2",
  "country": "US",
  "kind": "B2",
  "title": "Road paver with control unit for determining the weight and/or the center of gravity and/or the width of the screed and corresponding method",
  "abstract": "A road paver is provided with a drive, a bunker, a material conveying device, a screed comprising a tamping device and an electric heating device on the screed and/or on the tamping device, wherein a control unit is configured in such a manner that it determines, by means of a measurable electrical operating parameter of the electrical heating device on the screed and/or on the tamping device, the weight and/or the center of gravity and/or the width of the screed transversely to the working direction of the screed. A method for determining a width and/or a weight and/or a center of gravity of a screed of a road paver, comprising the steps: measuring an electrical variable of a heating device, in particular a heating power, a heating resistance or a power consumption of the heating device; calculating the weight and/or the center of gravity and/or the width of the screed transversely to the working direction of the screed by means of the electrical operating variable.",
  "claims": [
    "1. A road paver comprising: a drive; a bunker; a material conveying device; a screed and/or a tamping device; an electric heating device on the screed and/or the tamping device; a control unit; and a measuring device configured for measuring a heating power on the screed and/or on the tamping device and/or for measuring a resistance on the screed and/or on the tamping device and/or for measuring a power consumption on the screed and/or on the tamping device, wherein the control unit is provided which is configured to determine a weight and/or a center of gravity and/or a width of the screed, with the center of gravity and/or a width of the screed being determined transversely to a working direction of the screed, in response to a measurable electrical operating parameter of the electric heating device on the screed and/or on the tamping device as measured by the measuring device.",
    "2. The road paver according to claim 1, wherein the at least one electrical operating parameter is a heating resistance of the screed and/or of the tamping device or a heating power received by the screed and/or the tamping device or a power consumption on the screed and/or the tamping device.",
    "3. The road paver according to claim 1, wherein the screed and/or the stamping device has a variable size, which can be varied in particular by providing at least one add-on part.",
    "4. The road paver according to claim 1, wherein the control unit is configured for adapting an operating parameter of a drive control and/or of a material flow control and/or of a heating control as a function of the determined weight and/or of the determined center of gravity and/or the determined width of the screed transversely to the working direction of the screed.",
    "5. The road paver according to claim 1, wherein the control unit is configured for determining a paving volume considering a known paving height and the determined width of the screed transversely to the direction of operation of the screed.",
    "6. The road paver according to claim 1, wherein a hydraulic control arrangement is provided for controlling at least two actuating cylinders which are spaced apart from one another transversely with respect to the working direction, wherein the actuation cylinders are each connected at least indirectly on one side with a frame of the road paver and on the other side with the screed of the road paver, wherein the screed can be subjected to a load pressure and/or a relief pressure via the actuating cylinders, and wherein the control unit is configured to determine a desired load pressure and/or a relief pressure from the determined weight and/or center of gravity and/or width of the screed transversely to the direction of operation of the screed.",
    "7. The road paver according to claim 6, wherein the load pressure and/or the relief pressure can be adjusted by the control unit as a function of a defined operating state of the road paver, wherein the defined operating state includes a downtime of the road paver, an ascent of the road paver or an inclined position of the road paver.",
    "8. The road paver according to claim 7, wherein the control arrangement applies a relief pressure to the at least two actuation cylinders in the defined operating state of a downtime, an ascent or an inclined position.",
    "9. The road paver according to claim 7, wherein a device for determining a cylinder force of the at least two actuation cylinders is provided, which indirectly determines the relief pressure required in the defined operating state of the road paver via of a calculation of the mass of the screed and the center of gravity of the screed transversely to a working direction of the road paver.",
    "10. The road paver according to claim 9, wherein the device for determining the cylinder force determines the mass and the center of gravity of the screed on the basis of a measured heating power or a measured resistance or a measured power consumption.",
    "11. The road paver according to claim 9, wherein the device for determining the cylinder force further takes into account a hydraulic extension width of the screed, a speed of the road paver and/or a transverse and longitudinal inclination of the road paver to calculate the required cylinder force in order to provide the necessary relief pressure in the defined operating state of the road paver.",
    "12. The road paver according to claim 6, wherein the control arrangement controls a first actuating cylinder and a second actuating cylinder of the screed in order to provide the required relief pressure.",
    "13. A method for determining a width and/or a weight and/or a center of gravity of a screed of a road paver according to claim 1, comprising the steps: measuring an electric operating variable of a heating device; and calculating the weight and/or the center of gravity and/or the width of the screed transversely to the operating direction of the screed from the electric operating variable.",
    "14. The method according to claim 13, wherein the method further comprises the step of controlling a relief pressure and/or a load pressure of the at least two actuating cylinders which are spaced apart from one another transversely to the working direction and are each connected on one side to a frame of the road paver and on the other side to a screed of the road paver, wherein the screed can be subjected to a load pressure or a relief pressure via the actuating cylinders and a target value for a load pressure and/or a relief pressure necessary in a defined operating state of the road paver and corresponding to the calculated weight and/or the center of gravity position of the screed is determined.",
    "15. The method according to claim 13, wherein the method further comprises a step of detecting an actual value of a load pressure and/or a relief pressure.",
    "16. The method according to claim 13, wherein the method further comprises the step of controlling the at least two actuation cylinders for generating a load pressure and/or a relief pressure required for a defined operating state, and wherein the defined operating state comprises a downtime of the road paver, an ascent of the road paver or an inclined position of the road paver.",
    "17. The method according to claim 13, wherein the method comprises the adaptation of an operating parameter of a drive control and/or a material flow control and/or a heating control.",
    "18. The method according to claim 13, wherein the method comprises the determination of a paving volume considering a known paving height.",
    "19. The method according to claim 13, wherein the electric operating variable comprises a heating power, a heating resistance or a power consumption of the heating device."
  ],
  "description_excerpt": "The present invention relates to a road paver with a drive, a bunker, a material conveying device, a screed, comprising, in particular, also a tamping device, and an electric heating device on the screed and/or if present, on the tamping device. The present invention further relates to a method for determining a width and/or a weight and/or a center of gravity position of a screed of a road paver.\n\nWith conventional road pavers, especially with asphalt road pavers, it is well known that the paving screed (abbreviated in the following to “screed”) must be guided in a floating manner over the material to be paved during the working process. Such screeds may be designed as rigid screeds or as screeds with sliding parts. Adapting the paving screed to the desired working width is effected by the optional mounting of suitable add-on screed elements and/or by retracting and extending movable screed segments with respect to a basic screed. The width of the screed has a decisive effect on the work processes of the road pavers, for example, on how quickly the paver can travel during the laying of a support layer of a road, how much electricity has to be produced by a generator for supplying electric loads on the screed and how much paving material has to be transported from the material bunkers of the road finisher to the screed. Since the width of the screed is variable, the current width of the screed must be entered by the operator at the road paver to control the workflow.",
  "cpc": [
    "E01C 19/486",
    "E01C 19/30",
    "E01C 19/42",
    "E01C 19/48",
    "E01C 19/4853",
    "E01C 19/4873",
    "E01C 23/01",
    "E01C 2301/10",
    "E01C 2301/14"
  ],
  "ipc": [
    "E01C 19/30",
    "E01C 19/42",
    "E01C 19/48",
    "E01C 23/01"
  ],
  "assignees": [
    "Bomag GmbH and Co OHG"
  ],
  "inventors": [
    "Niels Laugwitz",
    "Michael Witsch",
    "Moritz Nick"
  ],
  "filing_date": "2017-03-14",
  "publication_date": "2019-04-16",
  "grant_date": "2019-04-16",
  "priority_date": "2016-03-18",
  "application_number": "US-201715458438-A",
  "family_id": "59751538",
  "cited_by_count": 4,
  "citations": [
    "US5356238A",
    "DE102004003356A1",
    "US7669458B2",
    "EP2233641A2",
    "US8930092B2",
    "US9367042B2"
  ]
}