Parking assistance device

A parking assistance device comprising:

• a sensor that detects an object;
• a guiding unit configured to guide a vehicle to a parking initial position from which the vehicle can be parked in a parking space, the parking space being located adjacent to and on a far side of the object located adjacent to the vehicle, the far side of the object being defined with respect to a running direction of the vehicle;
• a timing setting unit configured to set a timing to start guiding the vehicle based on a speed of the vehicle;
• and
• an obstacle detecting unit configured to detect an obstacle adjacent to the vehicle in response to a reflected wave of a wave emitted from the vehicle in a predetermined direction,
• wherein, when an obstacle is not detected, in the running direction of the vehicle, in the parking space within a predetermined distance from the object, the guiding unit starts guiding the vehicle, the predetermined distance being a reference length extending from the far side of the object in the running direction of the vehicle, and
• wherein the timing setting unit adjusts the predetermined distance based on the speed of the vehicle.