CONTROL DEVICE

A control device that may be a control device of a hybrid vehicle. The hybrid vehicle including an engine; an electric generator configured to generate electric power by operation of the engine; a battery configured to store the electric power; a traction motor configured to operate by the electric power stored in the battery; and a throttle valve configured to adjust an amount of air to be supplied to the engine. The control device is configured to estimate torque of the engine based on an output current value of the electric generator. The control device is configured to estimate an actual aperture of the throttle valve based on the estimated torque and revolution speed of the engine. The control device is configured to perform feedback control so that the aperture of the throttle valve is adjusted to the target aperture based on the estimated actual aperture.