Abstract: For each degree of freedom of the robot and in the COMMAND mode (switch 32 in position II) the corresponding movable member 21 is moved by an actuator 20 in accordance with an error signal formed as the difference between a command datum C supplied from a register 27 and an actual position datum P supplied by a position sensor 26, the command data required from time to time being provided from a memory 28 via a circuit 34. For training the robot, the FOLLOW mode is selected by putting the switch 32 in position I and the command datum C is replaced by the position datum P, the value of which is periodically entered in the register 27 via a switch 33 which is periodically closed by pulses 35a from a pulse generator 36. When the robot is at a position to which it is to be trained, a switch 30 is closed to write the then contents of the register 27 in the memory 28 for subsequent use in the COMMAND mode.