Crane and method for monitoring the operation of such a crane

A crane comprising:

• a boom from which a lifting hook is suspended via a hoist cable;
• a trolley from which hoist cable is suspended;
• drive devices for crane movements and/or load movements, wherein the drive devices comprise a slewing gear drive device, a hoisting gear drive device, a trolley drive device, a luffing drive device, and a telescoping drive device, wherein the boom is configured to be rotated about an upright rotation axis via the slewing gear drive device, wherein the lifting hook is configured to be raised and lowered relative to the boom via the hoisting gear drive device, wherein a horizontal outreach of the lifting hook from the upright rotation axis of the boom is configured to be increased or decreased via the trolley drive device, the luffing drive device, or the telescoping drive device, wherein the trolley drive device is configured to drive the trolley along the boom, wherein the luffing drive device is configured to luff the boom up and down about a horizontal transverse luffing axis, wherein the telescoping drive device is configured to telescope the boom;
• a crane controller for controlling the drive devices, wherein the crane controller comprises a monitoring device, wherein the monitoring device comprises a sensor for detecting a rotational position of the boom about the upright rotation axis, a load sensor for detecting a load attached to the lifting hook, and at least one of the following sensors:
• a trolley position sensor for detecting a trolley position along the boom, a luffing angle sensor for detecting a luffing angle of the boom about the horizontal transverse luffing axis, and a boom length sensor for detecting a telescoped boom length of the boom;
• wherein the monitoring device is configured to monitor crane strain and restrict crane movements when critical crane strains are reached
• wherein the monitoring device is configured to calculate a current overall center of gravity of the crane based on sensor signals representative of the load attached to the lifting hook, the rotational position of the boom about the upright rotation axis, and the horizontal outreach of the hoist cable from the upright rotation axis;
• wherein the monitoring device is configured to calculate possible future overall centers of gravity based on the calculated current overall center of gravity and possible crane movements that change the rotational position of the boom about the upright rotation axis as generated by the slewing gear drive device and that change the horizontal outreach of the hoist cable from the upright rotation axis as generated by at least one of the trolley drive device, the luffing drive device, and the telescoping drive device;
• wherein the monitoring device is configured to calculate distances of the calculated possible future overall centers of gravity from tipping edges of a support base of the crane stored in a data memory;
• wherein if some of the calculated possible future overall centers of gravity are outside the tipping edges, the monitoring device is configured to select one of the calculated possible future overall centers of gravity outside the tipping edges that is farthest from one of the tipping edges as a most critical overall center of gravity and wherein if none of the calculated possible future overall centers of gravity are outside the tipping edges, the monitoring device is configured to select one of the calculated possible future overall centers of gravity inside the tipping edges that is closest to one of the tipping edges as the most critical overall center of gravity;
• wherein the monitoring device is configured to calculate a remaining outreach reserve in terms of a possible increase of the horizontal outreach and a movement reserve for a possible rotational movement of the boom about the upright rotation axis for the selected most critical overall center of gravity;
• wherein the monitoring device is configured to shut down and/or slow down at least one of the trolley drive device, the luffing gear drive device, and the telescoping drive device in response to the calculated remaining outreach reserve being smaller than an allowable outreach reserve;
• wherein the monitoring device is configured to shut down and/or slow down actuation of the slewing gear drive device in response to the calculated movement reserve being smaller than an allowable movement reserve;
• and
• wherein the monitoring device is configured to determine displacements of the current overall center of gravity as a result of changes in different operating and/or influencing variables comprising different crane movements, and
• wherein the monitoring device is configured to determine a possible restriction of crane movements based on the selected most critical overall center of gravity.