Electric power steering device

An electric power steering control device for calculating a steering control amount for steering a steering device, the electric power steering control device, comprising:

• a basic control amount calculating section configured to calculate a basic control amount corresponding to steering by a driver;
• a frictional force calculating section configured to calculate, by using a friction model, a frictional force corresponding to a wheel angle-related value, which is a value relating to a wheel angle of the steering device, and calculate a friction-originated control amount, which originates from the calculated frictional force;
• and
• a control amount calculating section configured to calculate the steering control amount in accordance with the basic control amount and the friction-originated control amount calculated by the frictional force calculating section,
• the friction model being a model including a spring component and a Coulomb friction component connected in series,
• the frictional force calculating section being configured to:
• calculate the frictional force by using a plurality of models each being the model including the spring component and the Coulomb friction component connected in series,
• the plurality of models having respective spring constants and respective Coulomb friction forces,
• the plurality of models having respective ratios between the respective Coulomb friction forces and the respective spring constants, the ratios being different from each other;
• and
• output, in accordance with the wheel angle-related value, the frictional force which is to be output by driving the plurality of models, by sliding the plurality of models in ascending order of the ratios.