How does park assist work?

The first time a manufacturer sold a vehicle with automated parking functionality was Toyota in 2003 with its Prius hybrid model. Lexus quickly followed suit and introduced the LS 460 sedan that offered parallel and angled parking assistance. The functionality was revolutionary in the automotive world and had both the media and public excited about what the future held for semi-autonomous and autonomous driving functionality.

Since then the technology has developed even further with earlier and more basic renditions of the technology becoming more common in consumer vehicles. While the operation of the technology is quite intuitive is is quite strange for first-time users to surrender the steering inputs to the vehicle's computers. Let us explain what exactly happens when the function is activated.

How does it work?

A Park Assist system utilises multiple sensors and in some cases cameras too, situated in the front and rear of the vehicle as well as the sides, to measure the distance between the two vehicles. The driver activates the function by pressing a button indicating that they want to park. Using the measurements provided by the sensors and cameras, the system's computer will calculate whether or not your vehicle will fit in the space.

Once a large enough parking space has been identified by the Park Assist, it will instruct the driver where to park in order to perform the manoeuvre. In many cases, the driver will have to select the parking space on the infotainment screen and confirm they would like to park there before selecting the reverse gear. Now how the system functions from here, depends on the type of system the vehicle feature, below we list and explain all the most common systems.

- Steering assisted parking

This system is the most common and at the same time the most basic. This system relies on the driver for accelerator and braking inputs and will require the driver to switch between forward and reverse gears during the process. The only area this Park Assist system control is the steering inputs. 

Should the driver not be confident in the manoeuvre or want to start again, all they have to do is apply full brakes and take control of the steering wheel. With those inputs, the system will completely disengage and full vehicle control is given to the vehicle driver. 

- Steering assisted parking with exit

If a driver finds themself parked in or just not confident in exiting a parking space, this system utilises the same technology to assist the driver in getting out of a parking space. The basic operation remains the same where once the system is activated, will rely on the driver for gear selections and brake and accelerator inputs. Similarly, a driver can override the system by taking control of the steering while braking. To avoid accidentally cancelling the operation, it is best for the driver to completely release the steering wheel and keep their hands on their lap rather.

- Fully automated parking

The next tier up in the Park Assist technology is fully automated parking. As the name suggests, this type of Park Asssist system does everything for the driver. Thus it not only controls the steering inputs but the accelerator and braking inputs as well. While this will test a driver's faith in technology, the system usually requires the pilot to keep the Park Assist button depressed throughout the manoeuvre.

Should the driver release the button anywhere through the operation, the automated parking procedure is cancelled. Because the system controls not only the accelerator and braking inputs but selects gears as well, this system is only found on vehicles with an automatic transmission or electric vehicles that don't require manual gear changes.

- Remote-controlled parking

Remote-controlled parking utilises much of the same technology as featured with fully automated parking systems. The main difference here is that all occupants including the driver can exit the vehicle and from either a digital key fob, smartphone or even smartwatch, instruct and even guide the vehicle into a parking space. 

The vehicle will still rely heavily on information provided by proximity sensors and cameras but will only start executing the manoeuvre when the driver instructs it through a remote device. This is especially helpful in very tight parking spaces, where it is difficult for the driver to enter or exit the vehicle in its final parked position.