# A Real Time Algorithm for Versatile Mode Parking System and Its Implementation on FPGA Board
## 1 Introduction  
Nowadays, automatic parking systems function as an important component for new vehicle generations. The need to introduce an Autonomous and Versatile mode Parking System (AVPS) for the parking of future vehicles was the main motivation of this paper. It is expected that all vehicle manufacturers will adopt a unique configuration for automatic or semi-automatic parking, which takes the driver some minutes to find a parking lot that suits an already pre-programmed configuration. Before starting the presentation of the proposed AVPS developed system, we have studied a number of automatic parking systems of vehicles in the literature that have been developed by researchers in the field of automatic parking systems. Authors in [1] focused their research on the parallel motion planning using Poisson-disk sampling. The paper deals with a rapidly exploring-random-tree-based parallel motion planning algorithm that uses the maximal Poisson-disk sampling scheme. In paper [2], authors resolved the problem of generating a smooth parallel parking maneuver for autonomous car-like vehicles and formulated the problem in a point-to-ray framework connecting the parking position to all points in a neighborhood of the intermediate point. The proposed method was validated using a double-tracked Ackermann steering vehicle model. Implementation of an Autonomous Driving System using a smart phone for parallel and perpendicular parking was proposed by [PERSON] and [PERSON] [3]. The proposed system was carried out with theoretical algorithm and hardware integration;the result demonstrated the ability of vehicle parking. Authors in [4] also proposed an automated perpendicular parking system using approximated clothoid-based local path planning. The feasibility of the proposed technique was proven by the real-car test. A general two-step trajectory-planning algorithm from the robotics literature has been applied to generate suitable trajectories for an autonomous parking maneuver of a car [5]. In this study, the size of the parking space was taken into account by an adaptive choice of the maximum allowed velocity during the parking maneuver. It was reported [6] that, a variety of candidate paths was generated using a conventional back-propagation scheme for the path planning algorithm for the car-parking control problem. Optimal solutions were obtained with respect to performance measures, such as collision safety, moving distance, control efforts and so on. Many other works have been considered in studying parking behaviors and improving parking efficiency. Such research defines a specific model, which was built to understand the parking choice behavior, as presented in papers [7; 8; 9]. In most of these models, competing alternatives are already suggested prior to decisions. Otherwise, and firstly, a simple parking path programming strategy for an automatic parking system was provided [7]. This strategy employs the minimum turning radius of the vehicle by means of an infrared distance sensor to determine the parking path, simplifying its analysis without any need for the application of expensive sensors and complex mathematical calculations to determine the parking path. The vehicle would be able to achieve its parking safely and correctly in the parking lot simply by following these routes. Secondly, a novel smart parking system was proposed for an urban environment. The system assigns and reserves an optimal parking space based on time efficiency and minimal driver's effort. It exploits technologies for parking space availability detection and for driver localization, and allocates parking spots to drivers instead of only supplying guidance. To reach this objective, [PERSON] and [PERSON] [8] focused on selecting proper decision intervals and using pricing control to adjust parking space prices for different classes of users or other bidding-type mechanisms that can enhance fairness. Finally, [PERSON] et al. [9] developed a path planning method for parallel parking mode.