Method and system for following target

A system for following a target, comprising:

• a signal transmitting RF module, mounted on a target to be followed, working to send RF signals;
• a signal receiving RF module, mounted on a moving carrier, pairing with the signal transmitting RF module, working to receive the RF signals sent from the signal transmitting RF module;
• at least 3 laser rangefinders, mounted aside the signal receiving RF module, each calculating a relative distance between itself and the target;
• and
• a controller, signally connected with the signal receiving RF module and the at least 3 laser rangefinders, operating to calculate an estimated distance between the signal transmitting RF module and the signal receiving RF module, and a directional angle between a direction from the signal transmitting RF module to the signal receiving RF module and a normal direction to a front plane of the moving carrier where the signal receiving RF module is located by RF signals sent from the signal transmitting RF module and received by the signal receiving RF module, send commands to control moving of the moving carrier, and dynamically track the target by one of the laser rangefinders so that the relative distance is able to be successively calculated,
• wherein a first laser rangefinder has a tracing direction substantially along with the normal direction for sending and receiving laser beams;
• the controller keeps calculating the estimated distance and the directional angle and drives the moving carrier toward the target while maintains the directional angle substantially 0 degree until the estimated distance is shorter than a control exchange distance;
• when the estimated distance is shorter than the control exchange distance, the controller still calculates the estimated distance and the directional angle while drives the moving carrier to keep the relative distance within a predetermined range and maintain the normal direction substantially toward the target.