Electric steering apparatus having load detection function

An electric steering device having a vehicle load detection function, comprising:

• a handwheel sensor (110) configured to detect a handwheel torque according to steering angle adjustment of a handwheel (111);
• an electric steering motor (120) driven by a driving signal that controls a motor current to rotate the handwheel (111);
• and
• a steering controller (130) configured to output the driving signal when the handwheel torque is detected,
• wherein the steering controller (130) includes:
• a preprocessing unit (131) configured to receive a vehicle speed signal, a handwheel torque signal, and a motor current signal detected from the electric steering motor (120) and filter them to extract significant signal components;
• a signal classification unit (132) configured to classify the handwheel torque signal and the motor current signal extracted by the preprocessing unit (131) to correspond to a pre-designated vehicle speed range;
• a torque/current calculation unit (133) configured to calculate a handwheel torque value and a motor current value by integrating the handwheel torque signal and the motor current signal classified according to the vehicle speed range in the signal classification unit (132);
• a current/torque ratio calculation unit (134) configured to calculate a current-to-torque ratio that represents a ratio of a force assisted by the electric steering motor (120) to a total handwheel torque generated by the steering angle adjustment of the handwheel (111) using the handwheel torque value and motor current value calculated by the torque/current calculation unit (133);
• a comparison unit (135) configured to compare the current-to-torque ratio calculated by the current/torque ratio calculation unit (134) with a tolerance ratio value of a corresponding vehicle that has been stored in advance to determine whether a vehicle load is increased or decreased;
• and
• a driving signal output control unit (136) configured to output a driving signal for controlling a motor current applied to the electric steering motor (120) according to whether the vehicle load is increased or decreased as obtained by the comparison unit (135).