Method of excavating

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the excavation is carried out according to a pattern comprised of a sequence of superposed, in projection in a horizontal plane coinciding rectangular portions of the layer of soil, wherein said first and second predetermined levels are on a different level.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the angle of the grab with respect to the vertical is measured during insertion of the grab into the layer of soil by means of an inclinometer.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• h) wherein a projection of the area to be excavated is entered into a control and monitoring system for the excavating system in the form of a horizontal template of rectangles corresponding to the rectangular portions to be removed by the grab in an excavating step and determining the location of the grab required for each subsequent excavating step;
• and
• i) wherein the orientation of said horizontal template is selected depending on main profiles in the original surface of the layer of soil.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• h) wherein a projection of the area to be excavated is entered into a control and monitoring system for the excavating system in the form of a horizontal template of rectangles corresponding to the rectangular portions to be removed by the grab in an excavating step and determining the location of the grab required for each subsequent excavating step;
• and
• i) wherein the rectangles are selected to have a length and a width slightly smaller than the footprint of the grab, so as to enable a slight and known overlap of the area enclosed by the grab and the rectangular portions of the horizontal template.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• h) wherein a projection of the area to be excavated is entered into a control and monitoring system for the excavating system in the form of a horizontal template of rectangles corresponding to the rectangular portions to be removed by the grab in an excavating step and determining the location of the grab required for each subsequent excavating step;
• and
• i) wherein the original location and course of the surface of the layer of soil as well as of the desired location and course of the surface to be obtained by excavation of the layer of soil are entered into said control and monitoring system for the excavating device in the form of respective digital terrain models and combined with said horizontal template, the control and monitoring system dividing the area to be excavated into equidistant or parallel and adjacent subareas, each rectangle of the template comprising a plurality of such subareas or cells, and attributing a thickness value to each subarea, said thickness value corresponding to the difference in the levels of the actual surface and the desired surface for that subarea.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the actual position in the world of the grab is determined by a positioning system using local or global coordinate systems, the control and monitoring system being provided with a receiver for use in said positioning system.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the orientation of the grab in the horizontal and in the vertical plane is measured and supplied to the monitoring and control system for comparison to the grid orientation.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the grab is suspended from an arm/boom of the excavator and the orientation of the arm/boom, in the vertical plane relative to a vertical line through the excavator reference point, is measured and supplied to the monitoring and control system for determining the position of the grab reference point in that vertical plane.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:

• a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the orientation of the arm/boom in the horizontal plane relative to the excavator reference point, is measured and supplied to the monitoring and control system for determining the position of the grab in that horizontal plane.

A method of excavating a surface layer of soil by a using an excavator comprising a grab with two bucket halves having cutting edges, comprising the steps of:

• a) matching a horizontal template of parallel and congruent rectangles on the layer to be excavated, each rectangle having a centre;
• b) keeping the grab in open position defining a rectangular grab excavating opening having a grab centre,
• c) vertically matching the centre of a selected first rectangle and the grab centre and keeping the grab opening in a first orientation parallel to the rectangular portions of the horizontal template;
• d) positively lowering the cutting edges of the bucket halves into the layer of soil until their cutting edges reach a first predetermined level while maintaining said orientation,
• e) while maintaining that first level and first orientation, moving the bucket halves to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil,
• f) lifting the grab and moving the grab to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible,
• g) moving the grab towards a selected second rectangle of said horizontal template and keeping the grab in open position,
• h) vertically matching the centre of said second rectangle and the grab centre and keeping the grab opening in said first orientation;
• i) keeping the grab in said first orientation and lowering it into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level,
• j) while maintaining that second level and said first orientation, moving the bucket halves to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil,
• k) lifting the grab and moving it to a discharge position horizontally spaced from the first and second rectangles and emptied there to make further transport of the excavated soil possible;
• l) repeating steps g-k in a corresponding manner for excavating subsequent rectangles of said horizontal template until the layer of soil is excavated.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves with cutting edges, comprising the steps of:

• a) holding the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that first level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held controlled in a second orientation and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said second orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• and g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves with cutting edges, comprising the steps of:

• a) holding the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that first level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held controlled in a second orientation and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said second orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) including the steps of
• before step a), matching a horizontal template of congruent rectangles on the layer to be excavated, each rectangle having a centre and keeping the grab in open position defining a rectangular grab excavating opening having a grab centre,
• in said first excavating position vertically matching the centre of a selected first rectangle and the grab centre and keeping the grab opening in said first orientation during the lowering and closing of the cutting edges;
• and
• in said second excavating position vertically matching the centre of a selected second rectangle and the grab centre and keeping the grab opening in said second orientation during the lowering and closing the cutting edges.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves with cutting edges, comprising the steps of:

• a) holding the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that first level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held controlled in a second orientation and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and second orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein said first and second rectangular portions of said template are oriented towards one or more central points.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves with cutting edges, comprising the steps of:

• a) holding the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that first level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and removed to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held controlled in a second orientation and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said second orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the rectangles are selected to have a length and a width slightly smaller than that of the footprint of the grab, so as to permit a slight and known overlap of the area enclosed by the grab and the rectangular portions of the horizontal template.

A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves with cutting edges, comprising the steps of:

• a) holding the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation;
• b) while maintaining that first level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil;
• c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible;
• d) the grab is moved towards a second excavating position and held controlled in a second orientation and positively lowered into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level;
• e) while maintaining that level and said second orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil;
• f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible;
• g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated;
• and
• h) wherein the original location and course of the surface of the layer of soil as well as of the desired location and course of the surface to be obtained by excavation of the layer of soil are entered into a control and monitoring system for the excavating device in respective digital terrain models and combined with said horizontal template, the control and monitoring system dividing the area to be excavated into equidistant or parallel and adjacent subareas, each rectangle of the template comprising a plurality of such subareas, and attributing a thickness value to each subarea, said thickness value corresponding to the difference in the levels of the actual surface and the desired surface for that subarea.