A factory can send a car to exactly the right charging bay and still make a costly mistake if it has identified the wrong vehicle. Ford proposes checking that identity with a password flashed through the car’s lights before handing over automated control, according to a patent filing discovered by Carmoses.
Ford’s approach puts a visible identity check between a vehicle’s arrival on the wireless network and the start of automated movement. The proposed check applies to factories, depots, automated parking and charging facilities, where a mix-up can send the wrong car to a reserved space or a loading point.
Nothing in the filing names a specific model. We used the Mustang Mach-E for these renders because Ford has demonstrated automated factory marshalling with the electric SUV in Cologne.
Matching A Wireless Identity To A Car
Marshalling means moving vehicles around a controlled site under a central system’s direction. Before that system starts issuing driving commands, it needs to connect the identity arriving over its wireless network with a particular car in the camera view.
Ford identifies shortcomings in other approaches. Reading a license plate can depend on distance and vehicle orientation. Adding identification tags or reflective markers requires extra hardware on the car. A generic blinking challenge can also leave room for confusion between vehicles.
The proposed alternative starts with a wireless exchange of public keys, cryptographic values that each side can share. The car and the facility computer use those values with their own private keys to calculate the same shared secret. From that secret and an agreed code length, each independently calculates the light pattern it expects.
The facility then asks the vehicle to flash its lamps while cameras watch. Software compares the observed sequence with the expected answer, linking the physical car to the digital participant. An operator can confirm that a vehicle is available to begin the process, although Ford also allows that step to happen without operator confirmation.
The Pause Between Flashes Matters
In Ford’s worked example, a zero switches on the left turn signal and leaves the right one off. A one reverses those states. The sequence is 01110000, so the vehicle can transmit an eight-bit answer using familiar exterior lamps.
Between those bits, both selected lights go dark. These synchronization pauses help separate the signals. The example assigns 200 milliseconds to each code interval and 250 milliseconds to each dark interval, with timing chosen to suit the cameras’ ability to capture the flashes. Neither that speed nor the eight-bit length is fixed for every implementation.
The choice of lamps can change, too. Ford describes combinations involving headlights, brake lights, fog lights, mirror lights and parking lights. Its stated aims include distinguishing vehicles flashing simultaneously and reducing interference from an outside party.
A correct answer prepares the car for automated marshalling, but it still waits for subsequent driving instructions. If the observed pattern does not match, the system can request a new code. Failed identification can return the process to its initial stage with an error or suspended state for an operator to review. A faulty or busy lighting controller can also reject the flash request.
That makes reliable lamp control part of the handover, alongside wireless communication and camera recognition.
A Factory Problem With Wider Relevance
Ford’s E-Self demonstrations have already explored vehicles navigating within production facilities, parking and approaching charging stations under infrastructure guidance. That work establishes a practical use for identifying cars before moving them, without establishing that this particular authentication method was used.
BMW has taken automated movement into factory operation with the 5 Series and 7 Series at Dingolfing. Its system uses sensors along the route and an external movement planner. These projects make vehicle identity a practical concern for manufacturing, well before a customer encounters automated driving on a public road.
The security claims still need evidence. An eight-bit pattern offers only 256 combinations, so the security of the complete system depends on more than that short light sequence. Longer codes are possible, but Ford supplies no measured false-identification rate or demonstrated resistance to attacks. It also gives no performance results for reading the flashes in difficult lighting.
The strongest part of the proposal is its response to uncertainty. It provides a way to retry identification and withhold the control handover when the answer remains wrong. For automated charging and factory traffic, holding a car for review is preferable to sending an incorrectly identified vehicle into someone else’s space.
