Keyless access control device for motor vehicles and method for carrying out a keyless access authorization control in motor vehicles

A keyless access control device for a motor vehicle, the motor vehicle having a locked door and a door handle movable between first and second states, wherein in the first state the door handle is enabled to be actuated by a motor vehicle user in order to open the door when the door is unlocked, and in the second state the door handle is disabled from being actuated by a motor vehicle user, the device comprising:

• a controller associated with the motor vehicle and operable for moving the door handle between the first and second states, the controller further operable for unlocking the door;
• a transceiver associated with the motor vehicle, the transceiver operable for transmitting a low frequency (LF) code signal and for transmitting and receiving high frequency (HF) code signals;
• and
• a transponder associated with the motor vehicle user, the transponder operable for receiving an LF code signal and for transmitting and receiving HF code signals;
• wherein the transceiver transmits an LF code signal to the transponder and, in response, the transponder transmits a first HF code signal to the transceiver for low-level verification that the motor vehicle user has authorization to enter into the motor vehicle;
• wherein the controller moves the door handle from the second state in which the door handle is disabled from being actuated by a motor vehicle user to the first state in which the door handle is enabled to be actuated by the motor vehicle user in response to receipt and identification of the first HF code signal by the transceiver;
• wherein the transceiver transmits a transponder inquiry HF code signal to the transponder in response to actuation of the door handle by the motor vehicle user;
• wherein the transponder processes the transponder inquiry HF code signal to generate an encrypted HF code signal, wherein the transponder transmits the encrypted HF code signal to the transceiver for high-level verification that the motor vehicle user has authorization to enter into the motor vehicle;
• wherein the transceiver processes the encrypted HF code signal in order to determine whether the transponder is authorized to enable motor vehicle user entry into the motor vehicle;
• wherein the controller unlocks the door while the motor vehicle user is actuating the door handle in response to the transceiver indicating that the motor vehicle user is authorized to enter into the motor vehicle.