A monitoring system (100) monitors displacement of a wind turbine tower and includes at least one plumb bob with an upper part and a lower part, each plumb bob being configured to be pivotally suspended at its upper part, via a suspension device, from a point above so as to attain a rest position in a rest situation, and each said plumb bob has one or more sensing surfaces (12, 12′). One or more suspension devices means (10) suspend the at least one plumb bob. Two or more sensors (14, 14′, 14″), each being configured to sense, in a specific sensing direction (16, 16′, 16″), a distance to a plumb bob, provide displacement data. At least two of the two or more sensors (14, 14′, 14″) are arranged in a sensing vicinity of a plumb bob, with at least two of the specific sensing directions (16, 16′, 16″) not being parallel to each other. The monitoring system includes a control unit (18) configured to receive the displacement data from two or more of the sensors, and a device for reporting, to an external unit (20), parameter(s) representing displacement of a wind turbine tower.

A monitoring system (100) monitors displacement of a wind turbine tower and includes at least one plumb bob with an upper part and a lower part, each plumb bob being configured to be pivotally suspended at its upper part, via a suspension device, from a point above so as to attain a rest position in a rest situation, and each said plumb bob has one or more sensing surfaces (12, 12). One or more suspension devices means (10) suspend the at least one plumb bob. Two or more sensors (14, 14, 14), each being configured to sense, in a specific sensing direction (16, 16, 16), a distance to a plumb bob, provide displacement data. At least two of the two or more sensors (14, 14, 14) are arranged in a sensing vicinity of a plumb bob, with at least two of the specific sensing directions (16, 16, 16) not being parallel to each other. The monitoring system includes a control unit (18) configured to receive the displacement data from two or more of the sensors, and a device for reporting, to an external unit (20), parameter(s) representing displacement of a wind turbine tower.

A monitoring system (100) monitors displacement of a wind turbine tower and includes at least one plumb bob with an upper part and a lower part, each plumb bob being configured to be pivotally suspended at its upper part, via a suspension device, from a point above so as to attain a rest position in a rest situation, and each said plumb bob has one or more sensing surfaces (12, 12). One or more suspension devices means (10) suspend the at least one plumb bob. Two or more sensors (14, 14, 14), each being configured to sense, in a specific sensing direction (16, 16, 16), a distance to a plumb bob, provide displacement data. At least two of the two or more sensors (14, 14, 14) are arranged in a sensing vicinity of a plumb bob, with at least two of the specific sensing directions (16, 16, 16) not being parallel to each other. The monitoring system includes a control unit (18) configured to receive the displacement data from two or more of the sensors, and a device for reporting, to an external unit (20), parameter(s) representing displacement of a wind turbine tower.

An auto-charging system is disclosed. The system may comprise a base and a set of lower arms. The set of lower arms may comprise a first lower arm and a second lower arm each having a first end and a second end. The first end of the first lower arm may be attached to the base, and the second ends of the first and second lower arms may be attached to a hinge joint. The system may further comprise an upper arm having a first end attached to the hinge joint and a second end, a charger arm having a first end attached to second end of the upper arm and a second end, the set of lower arms, the upper arm, and the charger arm being foldable into the base, and a charger attached to the second end of the charger arm.

An auto-charging system is disclosed. The system may comprise a base and a set of lower arms. The set of lower arms may comprise a first lower arm and a second lower arm each having a first end and a second end. The first end of the first lower arm may be attached to the base, and the second ends of the first and second lower arms may be attached to a hinge joint. The system may further comprise an upper arm having a first end attached to the hinge joint and a second end, a charger arm having a first end attached to second end of the upper arm and a second end, the set of lower arms, the upper arm, and the charger arm being foldable into the base, and a charger attached to the second end of the charger arm.