Steering control device and steering control method for working vehicle

A steering control method that controls the steering operation of a working vehicle, comprising a vehicle speed detection means that detects the vehicle speed repeatedly at a first sampling period that is set in advance, and a steering angle detection means that detects the steering angle repeatedly at a second sampling period that is set in advance, in which are executed:

• a step of making a decision as to whether or not a third sampling period that is set longer than said first sampling period and said second sampling period has elapsed;
• a step of, when said third sampling period has elapsed, making a decision as to whether or not the vehicle speed being detected by said vehicle speed detection means is less than or equal to a reference vehicle speed that is set in advance;
• a step of, when said third sampling period has elapsed, making a decision as to whether or not the steering angle being detected by said steering angle detection means is changing by greater than or equal to a reference angle that is set in advance;
• and
• a step of deciding that stationary steering operation is being performed, if it has been decided that said vehicle speed is less than or equal to said reference vehicle speed and moreover said steering angle is greater than or equal to said reference angle.