Uniform User Interface for Semiautomatic Parking Slot Marking Recognition

Automatic parking systems consist of three core technologies: (1) target position designation; (2) path planning; and (3) path tracking. Target position-designation methods can be divided into four categories: (1) user-interface based; (2) parking slot marking based; (3) free-space based; and (4) infrastructure based. Considering the fact that parking-assist systems are expected to be used mainly in urban situations, recognition of parking slot markings could be the most economical and efficient solution for target position designation. This paper proposes a semiautomatic parking slot marking-based target position-designation method. The user can initiate parking slot marking recognition by placing a finger on each side of the entrance of the target parking slot. With such a user interface, these systems can reduce the search range to so small an area that computational loads and false-recognition rates are significantly reduced. Furthermore, by identifying the junction patterns of parking slot markings around the designated point with a neural network-based classifier, the user can establish the target position with a uniform user interface. The proposed system showed a 91.10% recognition rate in 191 test cases consisting of five different types of parking slot markings.