Machinery for an articulated arm carrying a tool (5), for example brush-cutting mower, comprises a jib (3) mounted on a carrier frame (1), a boom (4) mounted between the jib (3) and the tool (5), and at least one actuating mechanism (7a, 7b, 7c, 7e) at each articulation of the arm. The machinery also includes a device for managing the movement of the tool (5) in space in relation to the carrier frame (1). The managing device comprises at least one position sensor (6a, 6b, 6c, 6e) incorporated at each articulation of the arm, a central unit (9) connected to the at least one sensor (6a, 6b, 6c, 6e) for spatially positioning the tool (5) in relation to the carrier frame (1), and a coordinating unit (10) connected to the central unit (9), to the user interface (8) and to the actuating mechanisms (7a, 7b, 7c, 7e) of the arm.
