Automatically into the parking space.

  • 27. October 2014
  • Autonomous Driving
  • Text: Alexandra Knaup

Active Parking Assist with PARKTRONIC from Mercedes-Benz is part of the comprehensive vision of autonomous driving – and already a reality today.

Parking made easy: even well-versed motorists are grateful for the help provided by Active Parking Assist with PARKTRONIC from Mercedes-Benz. This advancement of the previously available PARKTRONIC system with parking guidance enables automatic parking in parallel and perpendicular parking spaces with automatic steering and braking interventions. In addition, the system is now also able to leave parallel parking spaces with automatic steering and braking interventions if the vehicle was previously parked automatically. This means added convenience especially in tight parking spaces.


Six ultrasound sensors in the front and six in the rear bumper are the “eyes” of Active Parking Assist. The sensors at the corners of the front bumper have a larger range to make them suitable for measuring the size of parking spaces while driving past them. At speeds below 30 km/h they check the right side of the roadway and detect suitable parallel and perpendicular parking spaces. If the left turn signal is activated, this process takes place correspondingly on the left side of the vehicle. A symbol in the instrument cluster indicates that the system is measuring.


Suitable parking spaces are identified by measuring the distance from the obstacle using sonar technology. The system determines how long it takes for the signal to travel to the obstacle and be reflected back to its source. The functions are controlled by a dedicated parking control unit. If a suitable parking space is identified, an arrow next to the symbol indicates the system’s ready state for automatic parking.


Once the system has found a suitable parking space, the driver can activate the automatic parking aid from the control panel on the multifunction steering wheel after stopping the vehicle and engaging reverse gear.


Active Parking Assist then takes control of the electromechanical steering system to automatically park the vehicle following a computed trajectory at a maximum speed of 10 km/h. In this process the system analyses the measurements of the depth and width of the potential parking space to determine whether it is a parallel or perpendicular parking space. The driver regulates the speed with the gas pedal. The entire parking process is designed to take a maximum of seven moves. In addition, Active Parking Assist now aids in parking on slightly curved streets.


AUTOMATIC LEAVING OF A PARKING SPACE Automatically leaving a parking space is only possible if Active Parking Assist was previously used for parking. Obstacles (e.g. vehicles) must be detected in front of the vehicle and behind. After the driver has switched on the ignition, activated the turn signal and has put the automatic transmission either in forward or reverse, the system asks whether to start the process of automatically leaving the parking space. If the driver confirms with “Yes,” the system takes control of the electromechanical steering and manoeuvres the vehicle out of the parking space in the direction of the activated turn signal. The driver has to operate the gas pedal for leaving a parking space as well. As soon as the vehicle has reached an angle from which the parking space can be left in one straight move (at the latest when the vehicle is at an angle of 45 degrees to the starting position), the wheels are straightened and the process is complete. The driver reassumes steering and braking duties. AUTOMATIC BRAKING The “automatic braking” function is active during automatic parking and leaving a parking space. This is made possible by a longitudinal control feature integrated into the ESP® system. It brakes automatically as soon as a certain distance from the end of the parking space is reached or an obstacle has been detected. The vehicle is braked to a stop just before reaching the obstacle. In addition, the engine torque is restricted to prevent the driver from accelerating too hard. To what extent the torque is restricted depends on the current position of the vehicle on the path into the parking space. SIDE PROTECTION The information from the PARKTRONIC sensors adds the “side protection” function to Active Parking Assist. If the system detects an obstacle on either side, the changing distance between the obstacle and the vehicle is determined. A computer model simulates the area on the side of the vehicle between the sensors. Depending on the distance to the obstacle, the system emits a multi-stage visual and audible warning as familiar from PARKTRONIC. The side protection function is active up to a speed of 18 km/h when the vehicle’s transmission is in position D, R or N. The side protection function allows preventing damages caused by obstacles located to either side of the vehicle that are obscured from the driver’s view. Because the position of moving objects outside the sensor range can merely be calculated, the system may warn of the obstacle in its original position even though it may have moved away.

Active Parking Assist enables automatic parking manoeuvring into parallel and perpendicular parking spaces with active steering and braking intervention.


A next evolutionary step could be fully automatic autonomous parking without a driver. Said driver gets out and prompts the car to find a parking space on its own and park automatically. A connection via smartphone could in turn let the vehicle know that the driver is ready to leave – and like with valet parking prompt it to pull up at the exit of the garage to meet the driver.

In August 2013, Mercedes-Benz became the first automaker to demonstrate with the S 500 INTELLIGENT DRIVE research vehicle that autonomous driving in intercity and city traffic is possible. Such a near-production and further developed sensor system also makes automatic parking without an occupant conceivable. In a first step this ability of the car to park autonomously will likely not be realized on completely unfamiliar terrain, but initially on “learned” routes such as the home garage.


  • Category

  • Function

    Automatic parking and leaving a parking space with active steering and braking intervention, the vehicle acceleration is controlled by the driver with the gas pedal.
  • Scope of delivery

    Control unit, 12 ultrasound sensors integrated into the bumpers, warning displays/graphics of the parking spaces in the instrument cluster
  • Availability

    Option for numerous model series

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