Systems and methods for monitoring and controlling tractor/trailer vehicle systems
A status of one or more subsystems positioned on one or more trailers is communicated to a tractor electrically and mechanically connected to the trailer. The status may be automatically supplied by the subsystem or may be requested either by the operator of the tractor/trailer combination or automatically by another subsystem on either the tractor or the trailer. A spread spectrum data communications signal representing the status of a respective subsystem is superposed on the power bus. The status of the respective subsystem can then be determined from the spread spectrum data communications signal. Preferably, the status of the subsystem is indicated to an operator positioned on the tractor. A command for controlling a subsystem on a trailer can also be communicated from the tractor to the trailer over the power bus. A spread spectrum data communications signal representing the command is produced on the power bus, and the subsystem is controlled based on the spread spectrum data communications signal. Preferably, the command is received from an operator positioned in the tractor.
1. A method of remotely monitoring a subsystem positioned on a vehicle that produces a data signal representing a status of the subsystem and a power bus which distributes electrical power to the vehicle, the method comprising the steps of:
producing a data communications signal from the data signal;
modulating the data communications signal to produce a spread spectrum data communications signal;
transmitting the spread spectrum data communications signal using the power bus;
remotely receiving the spread spectrum data communications signal; and
determining the status of the subsystem from the received spread spectrum data communications signal.
2. A method according to claim 1 , wherein said step of transmitting the spread spectrum data communications signal comprises the step of superposing the spread spectrum data communications signal on the power bus.
3. A method according to claim 1 , wherein said step of determining the status of the subsystem comprises the step of indicating said status of the subsystem to an operator of the vehicle.
4. A method according to claim 1 , wherein said step of determining the status of the subsystem comprises the steps of:
producing a data-modulated digital carrier signal including a plurality of transitions from the received spread spectrum data communications signal; and
detecting the status of the subsystem from the transitions of said data-modulated digital carrier signal occurring during a predetermined time interval.
5. A method according to claim 1 further comprising the step of communicating a command to the subsystem wherein said communicating step comprises the steps of:
producing a data communications signal representing the command;
modulating the data communications signal to produce a spread spectrum data communications signal;
transmitting the spread spectrum data communications signal using the power bus;
receiving the spread spectrum data communications signal; and
controlling the subsystem based on the spread spectrum data communications signal.
6. A method according to claim 5 , wherein said step of transmitting the spread spectrum data communications signal comprises the step of superposing the spread spectrum data communications signal on the power bus.
7. A method according to claim 5 , wherein said step of communicating is preceded by the step of receiving a command from an operator of the vehicle.
8. A method according to claim 5 , wherein said step of controlling the subsystem comprises the step of producing a command signal from the spread spectrum data communications signal.