A robot (3) comprises an arm having at least one joint (31, 31 ', 31 ") comprising a joint driving means (34, 35), the joint driving means having a plurality of actuation lanes; and a fault detection and isolation (FDI) system adapted to detect a fault in any one of the actuation lanes. The fault detection and isolation system in some embodiments is operable to isolate the or each actuation lane exhibiting the fault, and/or the robot (3) is provided with a local control system connected to the fault detection and isolation system, the control system being operable to control the operation of the joint (31, 31', 31 ") and to maintain, at least partially, operation of the joint (31, 31', 31 ") when a fault is detected.