Working crane control system to reduce the environmental impact of variable speed drives

A piloting system for piloting a crane in work, the piloting system comprising at least:

• a piloting interface configured to enable a crane operator to pilot displacement movements of a load by the crane;
• a control-command system connected to the piloting interface configured to receive piloting signals originating from the piloting interface and generate piloting commands according to the piloting signals;
• work actuators for implementing the displacement movements of the load;
• and
• variable-speed drives connected to the control-command system and to the work actuators and configured to receive the piloting commands originating from the control-command system and transmit to the work actuators speed setpoints according to the piloting commands,
• wherein at least one of the variable-speed drives is a first common variable-speed drive, and at least two of the work actuators are shared actuators, and
• wherein the at least one first common variable-speed drive is connected to the at least two shared actuators via a distribution relay, the distribution relay being piloted so as to alternately connect the at least one first common variable-speed drive with each of the at least two shared actuators, so that the at least two shared actuators function alternately.

A piloting method for piloting a crane in work, the method comprising at least:

• a piloting step in which a crane operator pilots displacement movements of a load by the crane on a piloting interface;
• a step of receiving piloting signals originating from the piloting interface by a control-command system connected to the piloting interface;
• a step of generating by the control-command system piloting commands according to the piloting signals;
• a step of transmitting the piloting commands to variable-speed drives which are connected to the control-command system and to work actuators for implementing the displacement movements of the load;
• and
• a control step in which the variable-speed drives transmit to the work actuators speed setpoints according to the piloting commands,
• wherein at least one of the variable-speed drives is a common variable-speed drive, and at least two of the work actuators are shared actuators,
• wherein the at least one common variable-speed drive is connected to the at least two shared actuators via a distribution relay, and
• wherein the piloting method further includes a switching step in which the distribution relay is piloted so as to alternately connect the at least one common variable-speed drive with each of the at least two shared actuators, so that the at least two shared actuators function alternately.