Automatic parking

Automatic parking is an autonomous car-maneuvering system that moves a vehicle from a traffic lane into a parking spot to perform parallel, perpendicular or angle parking. The automatic parking system aims to enhance the comfort and safety of driving in constrained environments where much attention and experience is required to steer the car. The parking maneuver is achieved by means of coordinated control of the steering angle and speed which takes into account the actual situation in the environment to ensure collision-free motion within the available space.

The car is an example of a nonholonomic system where the number of control commands available is less than the number of coordinates that represent its position and orientation.

One of the first assistance systems for car parking was manual. It used four jacks with wheels to raise the car and then move it sideways into the available parking space. This mechanical system was proposed in 1934, but was never offered on any production model.

One of the world's first experimental prototypes of automatic parallel parking was developed on an electric car Ligier at INRIA in the mid-1990s. The underlying technology has been adopted by major automobile manufacturers offering an automatic parking option in their cars today.

The automatic parallel parking algorithm localizes a sufficient parking place along the roadside, attains a convenient start location for the car in front of the parking place, and performs a parallel parking maneuver. Automatic pulling out involves localizing an available space for the car motion within the parking place, placing the car at an appropriate spot at the rear of the parking place, and performing a maneuver to pull out of the parking place into the traffic lane.

The key idea of automatic parking is to plan and parameterize the basic control profiles of steering angle and speed, in order to achieve the desired shape of the vehicle’s path within the available space. The parking maneuver is performed as a sequence of controlled motions using sensor data from the car servo-systems and range measurements about the environment. The steering and velocity controls are computed in real time and executed. The approach results in various path shapes required to perform parking maneuvers. It was extended to an automatic perpendicular parking on a CyCab electric vehicle in the early 2000s.

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Wikipedia