Vehicle access system

摘要

The invention relates to an access unit (5; 23) for communicating with a further access unit (5; 23) to control access to a vehicle (3). The access unit (5; 23) comprises at least a first transmitter (11; 25) for transmitting a polling signal; and at least a first receiver (11; 25) for receiving an authentication signal from the further access unit (5; 23) in response to the polling signal. At least the first transmitter (11; 25) is a first ultra-wideband transmitter and at least the first receiver (11; 25) is a first ultra-wide-band receiver. The invention also relates to a vehicle access system (1) which is a combination of the access and further access units (5; 23). The invention also relates to methods of operating a vehicle access system (1) and a vehicle access unit (5; 23).

主权项

1. An access unit configured to control access to a vehicle via communication with a further access unit, the access unit comprising:
a first transmitter configured to transmit a polling signal; and a first receiver configured to receive an authentication signal from the further access unit in response to said polling signal; wherein the first transmitter is a first ultra-wideband transmitter and the first receiver is a first ultra-wideband receiver; wherein the first transmitter is configured to pulse the polling signal with a time interval between transmissions; wherein the first transmitter is configured to:
increase the time interval between transmissions of the polling signal in response to an increase in a distance between the access unit and the further access unit; andreduce the time interval between transmissions of the polling signal in response to a reduction in the distance between the access unit and the further access unit,wherein the distance between the access unit and the further access unit is determined based on a time of flight of communications between the access unit and the further access unit, the first transmitter being configured to set the time interval in dependence on the determined distance; wherein the further access unit comprises a controller configured to authenticate a response signal transmitted from the access unit in response to said authentication signal; and wherein the controller is configured to initiate unlocking of at least one vehicle door when the distance between the access unit and the further access unit is less than or equal to a threshold range; and the controller is configured to initiate locking of at least one vehicle door when the distance between the access unit and the further access unit is greater than or equal to a threshold range.