Abstract: The present invention relates to remote radio control technology, and a remote radio control system includes a radio movable working machine (1), a remote control apparatus (6A), and a movable repeater station (7). First bidirectional communication means (31, 71) having a high radio wave directionality and first automatic tracking means (32, 71A) are provided between the working machine (1) and the repeater station (7), and second bidirectional communication means (63, 76) having a high radio wave directionality, second automatic tracking means (63A, 76A), and emergency spread spectrum bidirectional communication means (64, 87) for enabling bidirectional communication between the remote control apparatus (6A) and the repeater station (7) when communication by the second bidirectional communication means (63, 76) is impossible are provided between the remote control apparatus (6A) and the repeater station (7).

Abstract: In controlling a hydraulic excavator equipped with a front mechanism having multiple foldable and rotatable joints, the controlling method described enables complex joint actions to be controlled readily by manipulating electrical joy sticks. Translational and rotational control commands are input to a certain point on the longitudinal axis of a rear arm through the joy sticks and cooperative actions of multiple joints are achieved simultaneously.