Door and ramp interface system

Abstract

An access system for a vehicle includes an interface system that communicates with the vehicle data bus. The interface system also communicates with a ramp control subsystem that operates to stow and deploy a ramp for providing wheelchair access to the vehicle. A door control subsystem is coupled to the vehicle data bus and operates to open and close a vehicle door in response to data signals sent over the vehicle data bus. When the vehicle door is open and the ramp is deployed, the interface system is configured to send a ramp deployed data signal over the vehicle data bus, which prevents the door control subsystem from closing the door on the deployed ramp.

1 . An access system for a vehicle, the vehicle including a data bus, a door control system that opens and closes a vehicle door, and an activation signal source, the door control system and the activation signal source coupled to the data bus for communicating information via the data bus, the access system comprising:
 an interface system in communication with the data bus for communicating information via the data bus between the interface system and the activation signal source and the interface system and the door control system, the interface system operable to receive at least door activation signals sent on the data bus by the activation signal source and door status signals sent on the data bus by the door control system, the interface system operable to send a ramp status signal on the data bus;   a ramp control system in communication with the interface system, the ramp control system including a ramp that is movable between a stowed position and a deployed position in response to ramp operation signals received from the interface system,   wherein the interface system coordinates operation of the vehicle door and the ramp by sending a ramp deployed status signal on the data bus when the ramp is not in the stowed position, wherein sending a ramp deployed status signal on the data bus prevents the door control system from closing the door in response to a door activation request sent by the activation signal source when the ramp is not stowed, wherein the interface system responds to the door activation request by sending a stow ramp operation signal to the ramp control system, which responds by moving the ramp to the stowed position and sending a ramp stowed signal to the interface system, and wherein the interface system responds to the ramp stowed signal by changing the ramp status signal to thereby allow the door control system to close the door.   
   
   
       2 . The access system of  claim 1 , wherein the interface system further coordinates operation of the vehicle door and the ramp when the ramp is in the stowed position by monitoring the data bus for the door activation request sent by the activation signal source, waiting for the door control system to send a door fully open door status signal on the data bus, and sending a deploy ramp operation signal to the ramp control system in response to the door fully open door status signal. 
   
   
       3 . The access system of  claim 1 , further comprising a gateway module configured to relay communications between the data bus and the interface system. 
   
   
       4 . The access system of  claim 1 , wherein the vehicle includes at least one activation indicator that operates in response to a request to open or close the door, and wherein the interface system is coupled to the activation indicator to detect operation thereof in response to a request to open or close the door. 
   
   
       5 . The access system of  claim 1 , further comprising at least one door operation indicator that initiates a request to open or close the door, and wherein the interface system is coupled to the door operation indicator to determine when a request to open or close the door has been made. 
   
   
       6 . The access system of  claim 5 , wherein the door operation indicator includes a manually-operable button that sends a ground signal to a body control subsystem of the vehicle, and wherein the interface system is coupled to the button to detect the ground signal. 
   
   
       7 . The access system of  claim 1 , further comprising at least one door status indicator that detects when the door is fully open, and wherein the door status indicator is coupled to the interface system and sends a signal to the interface system to indicate that the door is fully open. 
   
   
       8 . An access system for a vehicle, the vehicle including a door control system operable to control movement of a vehicle door, a body control subsystem, and a vehicle data bus coupling the door control system and the body control subsystem for data communication, the access system comprising:
 an interface system coupled to the vehicle data bus for data communication with the door control system and the body control subsystem via the vehicle data bus, the interface system operable to detect a door operation request data signal sent via the vehicle data bus from the body control subsystem to the door control system, operable to send ramp status data signals over the vehicle data bus, and operable to send ramp operation signals; and   a ramp control system in communication with the interface system, the ramp control system operable to move a ramp between stowed and deployed positions in response to the ramp operation signals, and operable to communicate ramp status to the interface system, wherein when the door is closed and the ramp is stowed, the interface system responds to the door operation request data signal by monitoring for a door fully open signal, and in response to detecting the door fully open signal, the interface system sends a deploy ramp operation signal to the ramp control system, which responds by moving the ramp from the stowed position to the deployed position and by sending a deployed ramp status to the interface system when the ramp reaches the deployed position, and wherein the interface system sends a deployed ramp status data signal over the vehicle data bus in response to receiving the deployed ramp status from the ramp control system to thereby prevent the door control system from closing the door on the deployed ramp in response to additional door operation request data signals.   
   
   
       9 . The system of  claim 8 , wherein the door fully open signal includes a door fully open data signal sent over the vehicle data bus by the door control system. 
   
   
       10 . The system of  claim 8 , wherein the vehicle further includes a door operation indicator that sends a discrete electrical signal in response to an operator request for activation of the door, wherein the interface system is coupled to the door operation indicator to detect the discrete electrical signal, and wherein the interface system responds to the discrete electrical signal by moving the ramp from the stowed position to the deployed position. 
   
   
       11 . An access system for a vehicle, the vehicle including a door control system operable to control movement of a vehicle door, a body control subsystem, and a vehicle data bus coupling the door control system and the body control subsystem for data communication, the access system comprising:
 an interface system coupled to the vehicle data bus for data communication with the door control system and the body control subsystem via the vehicle data bus, the interface system operable to detect a door operation request data signal sent via the vehicle data bus from the body control subsystem to the door control system, operable to send ramp status data signals over the vehicle data bus, and operable to send ramp operation signals;   a ramp control system in communication with the interface system, the ramp control system operable to move a ramp between stowed and deployed positions in response to the ramp operation signals, and operable to communicate ramp status to the interface system, wherein when the door is open and the ramp is deployed, the interface system sends a deployed ramp status data signal over the vehicle data bus, wherein sending the deployed ramp status data signal over the vehicle data bus prevents the door control system from responding to the door operation request data signal, wherein the interface system responds to the door operation request data signal by sending a stow ramp operation signal to the ramp control system, which responds by moving the ramp from the deployed position to the stowed position and by sending a stowed ramp status to the interface system when the ramp reaches the stowed position, and wherein the interface system sends a stowed ramp status data signal over the vehicle data bus in response to receiving the stowed ramp status from the ramp control system to thereby allow the door control system to close the door.   
   
   
       12 . The access system of  claim 11 , wherein the door control system automatically operates to close the door in response to the stowed ramp status data signal.