Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR THE REMOTE
MONITORING AND CONFIGURATION OF ELECTRONIC
CONTROL SYSTEMS
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to communications systems employing
message transmitting stations and relay stations to send messages to mobile
vehicles. More specifically, the present invention relates to a novel and
improved method and apparatus for utilizing such communications
systems to enable remote monitoring and configuration of electronic control
systems within commercial freight transportation vehicles.
II. Description of the Related Art
A need is recognized by many in the mobile vehicle environment for
vehicle location and dispatch messaging capability. There are a substantial
number of commercial, governmental, and private applications requiring
the delivery of relatively short messages to or from a large number of
geographically dispersed terminals, or mobile transceivers, often on an
irregular basis. The need for message services includes, for example,
aviation, navigation, commercial transportation, and message delivery
services.
Other examples include the commercial trucking industry, where
dispatchers wish to communicate short messages to trucks located anywhere
in the continental United States, especially in rural areas. Until recently
the
transfer of such messages was restricted to periodic telephonic
communication between drivers and a central dispatcher. However, it
proved to be difficult, if not impossible, for drivers to consistently "call
in"
at fixed, scheduled, times since telephone services are not always readily
available in many areas.
Aside from conventional telephone systems, other communication
systems have attempted to address the mobile market. Radio telephone,
cellular telephone, and portable radio transceivers (CB) are all capable of
providing some form of communication between a mobile transceiver and
a base unit. However, a number of factors have rendered these systems
inadequate as message communication systems for serving a large number
of widely dispersed users. For example, the lower power transmissions
within each of an array of cells within cellular communication systems are
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prone to frequency selective fading and signal blocking.
Moreover, highly mobile units such as trucks are required to
frequently change channels as new cells within the cellular
system are traversed. Direct communication, non-cellular
radio systems have proven to be similarly disadvantageous
due to frequent system overload and susceptibility to
interference from other communications systems.
A communication system based on Earth orbital
relay satellites has been developed in an effort to overcome
these difficulties and provide for continuous delivery of
messages and related control information to a large number
of users over a wide geographic area. Such a satellite-
based message communication system is descxibed in, for
example, United States Patent No. 4,979,170, entitled
ALTERNATING SEQUENTYAL HALF DUFLEX COMMUNICATION SYSTEM,
which is assigned to the assignee of the present invention.
In addition to a dependence upon systems for
providing messaging capability to remote mobile units,
certain industries also share a requirement for reliable
mobile unit location information. One industry in
particular in which such information is particularly
desirable is the commercial trucking industry. In the
commercial trucking industry an efficient and accurate
method of vehicle position determination is in demand. With
ready access to vehicle location information, the trucking
company home base obtains several advantages. The trucking
company can keep the customer apprised of location, route
and estimated payload time of arrival. The trucking company
can also use vehicle location information together with
empirical data on the effectiveness of routing, thereby
determining the most economically efficient routing paths
and procedures.
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In U.S. Patent No. 5,017,926, entitled DUAL
SATELLITE NAVIGATION SXSTEM, which is assigned to the
assignee of the present invention, there is disclosed a
system in which the communications terminal at each mobile
unit is capable of determining position in addition to
providing messaging capability. The system of U.S. Patent
No. 5,017,926 relies upon the theory of triZateration in,
for example, the determination of mobile vehicle position.
Trilateration prescribes that if the position of three
objects are known relative to each other, and the distance
from each of these three objects to a fourth object is
known, then the three dimensional position of the fourth
object can be determined within the coordinate frame which
described the position of the first three objects. zn the
system of the U.S. Patent No. 5,017,926, the first two of
the three known positions
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correspond to the locations of a pair of satellites, while the third position
is
at the center of the Earth.
Using the satellite communication capability at each mobile terminal
to provide vehicle position determination offers great advantages to the
commercial trucking and related parcel delivery industries. For example,
this capability obviates the need for truck drivers themselves, via
telephones, to provide location reports regarding their vehicle position to
the trucking company home base. These location reports are intermittent at
best, because they occur only when the truck driver has reached a
destination or stopover site, and require the expenditure of the driver's time
to phone the trucking company home base. This method of location report
also leaves room for substantial inaccuracies. For example, truck drivers
may report incorrect location information either mistakenly or
intentionally; or report inaccurate estimates of times of arrival and
departure.
In contrast, the use of satellite communication capability at each truck
enables the location trucking company home base to identify the
longitude/latitude position of each truck at will, thus avoiding the
disadvantages associated with intermittent location reports. For example,
the down time (i.e., periods of zero revenue production) of idle trucks is
minimized since the communications necessary for determining location
could take place while trucks are en route. Also, inaccuracies in location
reports are virtually eliminated because the trucking company home base is
able to ascertain accurate truck location nearly instantaneously.
Recently, trucking and delivery vehicles have been equipped with
electronic control units (ECUs) connected to a vehicle data link. Such on-
board ECUs typically incorporate self-diagnostic features capable of, for
example, detecting faulty engine operation and vehicle subsystem failure.
Such ECU diagnostics tend to reduce maintenance costs by ensuring that
each vehicle is serviced in a timely manner subsequent to detection of
engine malfunction and the like. However, on-board vehicle electronic
processing and memory resources have been found to lack the capacity to
fully utilize the large amounts of data produced by increasingly sophisticated
electronic vehicle control systems. The limited on-board processing
capability of vehicle electronic control units have inhibited performance of
sophisticated diagnostic procedures, and have similarly limited the
execution of vehicle prognostics designed to anticipate vehicle servicing
requirements.
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In addition, many on-board ECUs are disposed to accumulate data
relating to vehicle operation. Specifically, data is transmitted over the
internal data link to an on-board recording device. However, the data
accumulated by the on-board recording device is typically of utility only
after
it has been transferred to a home base computer for use in analysis of
vehicle operation. The transfer of on-board data to the home base computer
is usually accomplished by downloading the on-board data to a portable
computer and physically transporting the computer to the home base. This
has proven to be a cumbersome process which is also both costly and prone
to error, especially within large vehicle fleets.
The operational parameters of many on-board vehicle ECUs may also
be programmed so as to optimize vehicle operation. For example, the
vehicle engine ECU may be set to prevent the vehicle from exceeding a
maximum vehicle speed. Again, however, adjustment of ECU parameters
is typically accomplished through manual connection of a specially
programmed portable computer to the vehicle electronic system. This
manual parameter adjustment process is similarly expensive and prone to
error.
During both the accumulation of on-board operational data and the
adjustment of ECU parameter settings, communication over the data link is
performed by using protocols which are proprietary to the manufacturer of
each ECU. The existence of multiple protocols adds cost and complexity to
the system, and precludes standardized communication over the vehicle
data link. Furthermore, existing proprietary protocols for communication
over the vehicle data link generally do not provide for reliable verification
of the identity of the devices currently connected to the link. That is, it is
typically incumbent upon vehicle drivers or service personnel to manually
maintain a record of various identifying information (e.g., manufacturer,
model number, software version) associated with each ECU connected to the
data link. Such manual verification methods are also obviously quite
susceptible to human error.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
standardized communication path between on-board vehicle electronic
control units (ECUs) and external data processing resources.
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It is a further object of the present invention
that convent.ional mobile communication systems, such as
satellite-based messaging and tracking systems, be employed
to implement the communication path.
5 It is yet another object of the present invention
to provide a system in which such a communication path be
used to enable off-board processing resources to perform
complex diagnostic and prognostic procedures involving
vehicle ECUs, thereby obviating the need for sophisticated
on-board processing capability.
It is still another object of the present
invention to enable a base station in radio or satellite
communicatiori with a vehicle to reliably identify devices
coupled to the vehicle's data link.
It is still a further object of the present
invention to provide a generalized communication protocol
capable of suppoxting the over-the-air transfer, between the
data link and an external processing resource, of
information formatted in a manner unique or proprietary to a
specific ECU.
It is still a further object of the present
invention to provide a generalized communication protocol
capable of supporting the transfer, between the data link
and an on-board vehicle display, of information formatted in
a manner unique or proprietary to a specific ECU.
It i$ still another object of the present
invention to enable the operational parameters of vehicle
ECUs to be monitored and/or adjusted from a base station in
radio or satellite communication with the vehicle.
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The invention may be summarized accordingly to one
aspect as a method for remotely monitoring and configuring a
vehicle subsystem located on a vehicle, said vehicle
subsystem being connected to a vehicle data link, said
vehicle being one of a fleet of vehicles in communication
with a central base station, comprising the steps of:
providing, within said vehicle, a message packet including
status information produced by the vehicle subsystem within
said vehicle, said message packet further including header
infoxmation identifying said vehicle and said vehicle
subsystem; transmitting said message packet from said
vehicle to said central base station; and directing said
message packet to a specific vehicle subsystem application
program at said central base station as a function of said
header information identify3.ng said vehicle subsystem for
monitoring and configuring said vehicle subsystem.
According to another aspect the invention provides
a method for remotely monitoring and configuring a vehicle
subsystem located on a vehicle, said vehicle subsystem being
connected to a vehicle data link, said vehicle being one of
a fleet of vehicles in communication with a central base
station, comprising the steps of: generating, at said
central base station, a message packet for receipt by a
vehicle subsystem within said vehicle, said message packet
including header information identifying said vehicle and
said vehicle subsystem; transmitting said message packet
from said central base station to a mobile communications
terminal of said vehicle; comparing said header information
of said message packet to corresponding vehicle subsystem
identifying information stored within a database located
onboard said vehicle; and placing said message packet upon
said vehicle data link if said header information matches
sald corresponding vehicle subsystem identifying information
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within said database for directing said message packet to
said.vehicle subsystem identified by said vehicle subsystem
identifying information.
According to another aspect the invention provides
a communication network for remotely monitoring and
configuring a vehicle subsystem located on a vehicle, said
vehicle subsystem being connected to a vehicle data link,
said vehicle being one of a fleet of vehicles in
communications with a central base station, said
communication network comprising: means for placing message
packets upon the vehicle data link of said vehicle, said
message packets indicating the status of at least one
vehicle subsystem within said vehicle wherein each of said
message packets includes header information identifying at
least one vehicle subsystem; a mobile communications
terminal, connected to the vehicle data link of said
vehicle, for transmitting said message packets from said
vehicle to said central base station; and means for routing
said message packets to vehicle subsystem application
programs within said central base station as a function of
said vehicle subsystem identifying information contained in
said header information.
According to another aspect the invention provides
a communication network for remotely monitoring and
configuring a vehicle subsystem located on a vehicle, said
vehicle subs,ystem being connected to a vehicle data link,
said vehicle being one of a fleet of vehicles in
communications with a central base station, said
communication network comprising: a message program,
resident within said central base station, for generating a
message packet for receipt by a vehicle subsystem within
said vehicle, said message packet including header
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information identifying said vehicle and said vehicle
subsystem; a mobile communication terminal, disposed at said
vehicle, for receiving said message packet wherein said
message packet is retrievable by said vehicle subsystem from
the vehicle data link; a database located withi.n said mobile
communications terminal containing vehicle subsystem
identifying information corresponding to said vehicle
subsystem; and a comparator module located within said
mobile communications terminal for comparing said header
information of said message packet to corresponding vehicle
subsystem identifying information within said database and
placing said message packet upon said vehicle data link if
said header information agrees with said corresponding
vehicle subsystem identifying information with said database
for directing said message packet to said vehicle subsystem
identified by said vehicle subsystem identifying
information.
SRIEF DESCIZIPTION OF THE DRAWINGS
The features, objects, and advantages of the
present invention will become more apparent from the
detailed description set forth below when taken in
conjunction with the drawings in which like reference
characters identify correspondingly throughout and wherein:
FIG. 1 depicts an exemplary implementation of a
mobile communications network;
FIG. 2 schematically represents a vehicle data
link included within a particular fleet vehicle;
FIG. 3 shows a more detailed representation of the
structure and organization of central and service provider
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control stations included within a mobile communicati,ons
network; and
FIG. 4 illustratively represents a set of three
fleet vehicles administered by fleet operator and service
provider base stations.
DETAYLED DESCRIPTION OF THE PREFERRED E1d8ODIMENTS
1. Introductioa
The present invention provides a method and
apparatus for transferring messages between the vehicle
subsystems within one or more fleet vehicles and one or more
central control stations managed by fleet operators or
service providers. Each vehicle includes a mobile
communications terminal, as well as an internal data link to
which are connected the vehicle subsystems. In accordance
with the invention, status information and the like generated
by each vehicle subsystem is placed on the internal data link
in the form of discrete message packets. Each message packet
includes header information identifying at least a specific
vehicle subsystem. Certain of the message packets will be
transmitted by the mobile communications terminal to a
network management center or like networking routing
facility, from which the packets are forwarded to a central
control station of a fleet operator which may be located at
the fleet operator dispatch facility. Within the central
control station, znformation is
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extracted from the received packets and catalogued into a database of vehicle
status information.
The central control station also transmits control requests and
parameter information to the mobile communications terminal of a
specified vehicle for use by various vehicle subsystems therein. Each
message packet generated by the central control station includes header
information identifying at least a particular fleet vehicle and vehicle
subsystem. This allows each message packet received by a particular mobile
communications terminal to be placed upon the vehicle data link and
retrieved by the specified vehicle subsystem.
II. Overview of Mobile Communication Network
FIG. 1 depicts the components of a mobile communication network
in which the present invention may be embodied. The mobile
communication network may comprise, for example, a conventional
cellular communication system designed to provide service between user
vehicles within specified geographic areas (i.e., cells). Alternately, the
present invention may be embodied within a satellite communication
system of the type capable of facilitating communication between one or
more central control stations and a plurality of user vehicles distributed
over a wide geographic area. Such a satellite-based message communication
system is described in, for example, the above-referenced United States
Patent No. 4,979,170.
Referring now to FIG. 1 in greater detail, an overview is provided of a
communication network 10 within which message information may be
exchanged between fleet vehicles 12, 14 and one or more control stations in
accordance with the invention. In FIG. 1, a communication network 10 is
illustrated in which the fleet vehicles 12, 14 each have a mobile
communications terminal (MCT). The fleet vehicles 12, 14 are
representative of any of a variety of vehicles (e.g., freight trucks) whose
drivers or other occupants desire to obtain occasional or updated
information, status reports, or messages from a fleet operator central base
station or central control station 18. As an example, truck drivers or other
delivery personnel often have a need for ready access to messages for more
efficient operation. The communication network of FIG. 1 relies upon a
satellite communication link between the vehicles 12, 14 and central control
station 18. However it is again noted that the teachings of the present
invention are equally applicable to terrestrial cellular or mobile radio
communications systems in which communication is established with one
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or more mobile units through a central facility and remotely located
transceiver base stations.
In order to provide appropriate context for a description of the
manner in which the present invention facilitates information exchange
between each internal vehicle data link and the central control station 18, a
brief description is first provided of the usual manner in which messages
are transferred between vehicle drivers and control stations.
III. Network Message Transfer
Referring now to FIG. 1 in greater detail, messages from the mobile
communications terminals of the vehicles 12, 14 are transmitted to the
satellite 20 and relayed thereby to a central terminal 22 which may also be
referred to as an Earth station. The central terminal or Earth station 22 can
be placed at a location proximate the central control station 18 allowing
lower site costs and local, direct access to transmission equipment for
maintenance and system upgrade. Alternatively, the Earth station 22 is
located in a remote location more ideally suited for low interference
ground-to-satellite transmission or reception. In this case, a telephonic,
optical or satellite communication link is utilized to establish
communication either directly between the Earth station 22 and the central
control station 18, or alternately between the Earth station 22 and central
control station 18 by way of a network management center (NMC) 24.
When messaging is to take place not only between the vehicles 12, 14 and
the central control station 18, but also between the vehicles 12, 14 and one
or
more service provider base stations or service provider control stations 28,
the NMC 24 enables more efficient control over the priority, access,
accounting, and transfer characteristics of message data. Additional details
of the communication hardware utilized in an exemplary implementation
of the Earth station 22 and NMC 24 are described in the aforementioned U.S.
Patent. No. 4,979,170.
Messages, or message data, for transmission to the mobile
communications terminal of each vehicle are transferred into the Earth
station 22 from the central control station 18. Such messages can be
provided to the Earth station 22 directly as digital data, or alternately are
keyed in by system operators to form the desired message signals. Each
message signal can be subjected to a variety of conventional coding,
encryption, or error detection and correction schemes prior to transmission.
Within the Earth station 22 encoded message symbols are used to modulate
a frequency generator or source such as a direct digital synthesizer which
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creates an FM modulated carrier, at a preselected frequency, which is
up-converted to the desired EHF band for transmission to the satellite 20.
To decrease interference and accommodate a large number of mobile
communications terminals at potentially different burst rates, in the
preferred embodiment a Time Division Multiplexed (TDM) transmission
scheme is used. Messages or message signals transmitted within the
network 10 are allocated TDM time slots (i.e., channels) of predetermined
length. The allocated time slots or channels are of very short duration, and
their interleaving across successive frames is made to be very large in order
that communication appear to be simultaneous to each mobile
communications terminal. Methods and apparatus for generating,
transmitting and controlling TDM signals are well known in the
communication art and can be accomplished using a variety of signal
multiplexing and control devices.
Each frame consists of a number of channels which represent
substantially identical, sub-frame length periods during which symbols are
transferred. This means that messages or message signals are transferred a
few bits at a time during each successive frame until the message is
completed. Information is generally sent over the communication channels
in discrete packets ranging in length from, for example, 4 to 256 characters.
Each packet is generally segmented into fields of information such as the
type of message, the length of the message, and the checksum bits. In
addition, each message is typically preceded by a header which includes an
individual serial number specifying a single mobile communications
terminal, a group address identifying a set of mobile communications
terminals, or an all-call address corresponding to all of the mobile
communications terminals within the system. By providing these alternate
addresses to which a mobile communications terminal can respond, it is
possible to efficiently transfer single messages to designated groups of
mobile communications terminals.
At each mobile communications terminal a transceiver is employed
to receive and demodulate communication downlink signals received from
the satellite 20. The downlink signals are received by an antenna and
transferred through a diplexer into a demodulator (each not shown) for
demodulation. The demodulator employs elements known in the art for
down-converting the received communication signal to a lower IF
frequency level, and then to a symbol frequency level as an encoded symbol
stream (i.e., digital message). The digital message may be provided to a
vehicle operator using a display device such as, for example, an LED, LCD,
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electroluminescent or discharge type element character display.
Alternatively, the message may be interfaced to other processing elements,
such as a portable computer, or printed out by a hard copy device such as a
5 small thermal printer.
IV. Communication with Vehicle Subsystems
In accordance with the invention, each mobile communications
terminal is connected to the internal data link of the vehicle upon which it
is mounted in order to serve as a conduit for transferring information from
10 designated data packets between the internal vehicle data link and the
network management center (NMC). The header information of each such
message is modified to include, in addition to an MCT serial number, a
vehicle subsystem message identifier (MID) associated with a particular
vehicle subsystem of the vehicle upon which the mobile communications
terminal is mounted. Exemplary vehicle subsystems include the vehicle
engine, braking system, electronic ignition system, and the like. In this way
specified message packets received by the mobile communications terminal
from a control station via the NMC 24 are placed upon the internal vehicle
data link and retrieved by the appropriate vehicle subsystem. Similarly, the
header information from data packets generated by vehicle subsystems are
generated so as to include the corresponding subsystem MID, as well as the
serial number of the mobile communications terminal to which the
subsystem is connected via the internal vehicle data link. In this way the
subsystem message may be identified by the recipient control station as being
generated by a particular vehicle subsystem. It is a feature of the present
invention that this bidirectional message transfer between selected vehicle
subsystems and the control station may be effected using existing
communication hardware, and requires no intervention by the vehicle
driver.
Turning now to FIG. 2, there is schematically represented a vehicle
data link 32 of the first vehicle 12. Connected to the data link 32 are a
mobile
communications terminal (MCT) 34, and a plurality of vehicle subsystems
31A - 31N each controlled by a vehicle electronic control unit (ECU) therein,
the ECU not shown. In a preferred embodiment information is conveyed
over the data link 32 in accordance with standards for vehicle data links
promulgated by the Society of Automotive Engineers (i.e., SAE J1587 and
SAE J1708), it being understood that other physical data links and/or
protocols may be employed without departing from the scope of the present
invention. The SAE J1708 and SAE J1587 standards respectively specify the
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physical structure of a standard data link, as well as the messaging protocol
employed in communication over the data link.
In accordance with SAE J1587, information is transferred using short
information packets of a variety of types. Each packet incorporates a field
specifying the originating ECU's MID, a field specifying data type, and a
field
relating to error detection. The content of the body of nearly all such
messages is fully specified, according to data type, by SAE J1587. In
addition,
the SAE J1587 protocol provides for data types allowing for connection mode
transfer of free-formatted data. As is described herein, the present invention
makes use of a variety of data packets defined by the J1587 specification.
V. Device Information Monitoring
In the present system, identification of devices on the data link is
effected using standard interrogative requests specified by SAE J1587.
Alternately, communications protocols unique to each vehicle ECU may be
employed by the MCT during the process of acquiring identifying
information from those of the vehicle ECUs enabled for communication
with the MCT. In an exemplary implementation, the fleet operator central
control station designates vehicle subsystems for device identification via
the satellite interface 37. Following each engine activation (e.g., engine
start
or ignition) or other predefined event, the device monitor 39 queries each
designated subsystem via the bus interface 35 for identification information
relating to its software and component parameters. The device monitor 39
stores this identification information within a database, a portion of which
is replicated within the central control station by way of the satellite
interface 37. TABLE I below specifies the fields included within an
exemplary record stored within the database of the device monitor 39.
TABLE I
Component
(MID)
VMRS
Model Number
Serial Number
Software Version
Number
Referring to TABLE I, a message identifier (MID) uniquely associated
with a given subsystem is stored within the Component field. Within the
VMRS field, an alphabetical entry is used to identify the manufacturer of the
subsystem or component specified in the Component field. In addition, the
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manufacturer's model number of the component is stored in the Model
Number field. Finally, the Serial Number of the ECU of the specified
component, and the software version utilized within this ECU, are
identified within the Serial Number and Software Version Number fields,
respectively. In an exemplary embodiment, the MCT provides selected
information stored within the database of the device monitor 39 to the
central and other control stations by way of the network management center
(NMC) 24.
In the exemplary embodiment, MCT 34 verifies the identity of the
hardware and software of the vehicle ECUs on the vehicle 12 at
predetermined times or intervals, for example at start up. This procedure
ensures that "mismatches" cannot occur in messages sent between central
control station 18 and vehicle 12. In the exemplary embodiment, device
monitor 39 queries vehicle subsystems 31A-31N by sending a query message
on vehicle data link 32. In the exemplary embodiment, vehicle subsystems
31A-31N respond to the query by providing the information designated in
TABLE I. Vehicle subsystems 31A-31N respond by providing the response
information on vehicle data link 32.
In addition, when MCT 34 detects a change in the identity of vehicle
subsystems 31A-31N, vehicle 12 transmits a message indicating the change
in the identity of the vehicle subsystems 31A-31N to central control
station 18. This allows central control station 18 to verify the identity of
the
vehicle subsystem 31A-31N which are targeted for inquiry. In the exemplary
embodiment, the transmission of this information is provided when when
engaging in data transfer with vehicle 12.
In a preferred embodiment, the identity of vehicle subsystems 31A-
31N, which are allowed to transfer data to central control station 18 are
configurable by messaging from either central control station 18 or service
provider control station 28. This subsystem configuration data is
transmitted to vehicle 12 as described above. In response to the subsystem
configuration data, MCT 34 sends a configuration message to vehicle
subsystems 31A-31N on vehicle data link 32. The subsystem of vehicle
subsystems 31A-31N which is to be reconfigured, receives the message and
in response alters its configuration.
VI. Free-Formatted Data Transfer
In order to facilitate the exchange of ECU-specific or proprietary
information between an ECU and an external control station processing
resource, the present invention contemplates use of the J1587 free-formatted
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information transfer protocol. Specifically, forward message packets
comprised of free-formatted data may be sent, via the NMC, to a vehicle's
MCT and relayed to an identified ECU via the vehicle's data link. Such
forward message packets may include, for example, parameter settings or
other information of like type used by an ECU during control of a given
subsystem. Similarly, ECUs coupled to the data link may send free-
formatted packets to the MCT for transmission, via the NMC, to one or
more control stations. As is described below, the central control station is
adapted to send message packets to particular vehicles identifying those
types of ECUs coupled to the vehicle's data link for which such free-
formatted message transfer is authorized.
Referring to FIG. 2, upon reception by the satellite interface 37 of a
message packet enabling a particular ECU to engage in free-formatted packet
communication, the satellite interface signals the device monitor 39 to
maintain a current record of information identifying the particular ECU
within an ECU identification database internal to the device monitor 39. As
described above, all or part of each identification record maintained by the
device monitor 39 may be replicated in a corresponding ECU identification
database within the central control station. As is explained below, the
maintenance of these databases of ECU identification information facilitates
verification that the information within each free-formatted message packet
is of a format consistent with the types of ECUs to which it is addressed.
This feature of the invention may be appreciated by considering the
case in which the MCT of a vehicle receives message packets from one or
more control stations, each message packet containing free-formatted
information and header information specifying the identity of an ECU
within the vehicle. In addition, the header information of each free-
formatted message packet will typically include identifying information of
the type included within TABLE I. The device monitor 39 compares the
header information of a received message packet to the identification
information within a corresponding record of the ECU identification
database therein. Message packets having header information consistent
with that stored within the ECU identification database of the device
monitor 39 are transmitted over the vehicle data link via the bus
interface 35 to the identified ECU. If the header information of a message
packet does not match that stored within the ECU identification database
internal to the device monitor 39, an error message is transmitted via
satellite interface 37 to the control station from which the message packet
originated. Accordingly, each vehicle ECU is precluded from receiving
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information formatted in a manner potentially inconsistent with its
required message protocols and the like.
Those ECUs connected to the vehicle data link which have been
authorized for message transfer by the device monitor 39 of the vehicle
MCT may also be authorized to transmit message packets to one or more
control stations. Messages are transmitted over the vehicle data link from
an authorized ECU to the vehicle MCT in the form of, for example, J1587
free-formatted message packets. In turn, the satellite interface 37 of the
vehicle MCT transmits the free-formatted data inherent within the message
packets to one or more control stations. The header information of these
free-formatted packets typically includes the MID of the ECU from which the
packet originated. In addition, the header information may also include
information relating to the routing of the packet to specific control
stations.
In this regard the central control station may place constraints, transmitted
to and stored within the device monitor 39, relating to the type of ECUs
which may transmit free-formatted information to particular control
stations. For example, by providing a "routing VMRS" to the device
monitor 39 the central control station may specify that vehicle ECUs of a
particular MID may transmit free-formatted information only to those
control stations associated with the manufacturers identified by a
corresponding VMRS value. The device monitor 39 facilitates compliance
with this constraint by verifying that the VMRS field of the ECU sending the
message matches the routing VMRS (i.e., the actual manufacturer of the
ECU) associated with the MID of the ECU. In this way it is ensured that
message packets from the ECUs of a given manufacturer are routed to the
control station or processing facility associated with the manufacturer. After
such message packets are transmitted by the MCT 34 via satellite 20 and
Earth station 22 to the NMC 24, NMC 24 routes the transmitted message
packets to the appropriate control station using the MID and routing VMRS
fields within the message packet header.
Although the foregoing indicates that a control station may
authorize, for example, via an over-the-air communication, a vehicle MCT
to send and receive message packets associated with a particular ECU, it
should be understood that other methods of authorization are within the
scope of the present invention. For example, the MCT may be configured to
locally receive authorization, via user interface 36, for
transmission/reception of free-formatted message packets associated with a
given ECU.
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Referring to FIG. 3, there is shown a more detailed representation of
the structure and organization of the central control station 18 and of the
service provider control station 28. As is indicated by FIG. 3, the NMC 24 is
connected through telephone lines or dedicated fiber optic cables to the
5 central and service provider control stations 18, 28. The central control
station 18 is seen to include a general purpose computer system (e.g., an IBM
AS/400) having a central processing unit (CPU) 50 that is interconnected by a
system bus 52 to a primary memory module in which are stored a messaging
program 60, a router program 61, and one or more vehicle system
10 application programs 62. The CPU 50 is also connected to a keyboard 64, as
well as to an interface display driver 66 in combination with a display device
70.
The messaging program 60 sends the free-formatted message packets
originating within various vehicle subsystems to the router program 61, and
15 transfers other types of control messages and information received from the
NMC 24 to the system bus 52. The messaging program 60 may be
implemented using software such as the QTRACS/400 program available
from QUALCOMM Incorporated of San Diego, California. Based on the
vehicle subsystem MID included within the header information
accompanying each message packet, the router program 61 relays each
received message packet to one or more vehicle system application
programs 62. The vehicle system application program(s) 62 will typically be
designed to, for example, monitor vehicle subsystem performance, maintain
statistics related to vehicle subsystem operation, and forecast vehicle
service
requirements.
Referring to FIG. 3, a vehicle database 72 maintained within the
central control station 18 includes a record of the types of ECUs utilized
within the vehicle associated with each mobile communications terminal.
In an exemplary embodiment the vehicle database 72 is formed by
replicating, within the central control station 18, at least the portion of
the
database within each mobile communications terminal specifying the MCT
serial number and the identifying information for the ECUs contained
within the vehicle upon which is mounted the mobile communications
terminal. The existence of the vehicle database 72 and/or the database
within each mobile communications terminal advantageously prevents
parameter or control information of incorrect format from being provided
to or from a given ECU.
Specifically, the messaging program 60 can operate to verify that the
header information of each message packet intended for receipt by an ECU
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agrees with the corresponding information stored within the vehicle
database 72. The messaging program 60 accomplishes this by comparing the
ECU information specified within the packet header to the ECU information
stored within the record of the vehicle database 72 associated with the
mobile communications terminal specified by the packet header. If the ECU
information specified within the packet header does not agree with the
identifying information for that ECU type within the database record, an
error message is generated and the message packet is not sent.
As is indicated by FIG. 3, the service provider control station 28 is
organized similarly to the central control station 18. Accordingly, primed
reference numerals have been used to identify elements within the service
provider control station 28 substantially similar to those within the central
control station 18. Disposed within the service provider control station 28 is
a general purpose computer system (e.g., an IBM AS/400) having memory
in which is stored a messaging program 60', a router program 61', and one
or more service provider application program(s) 74. Each service provider
application program 74 is enabled for operation by the central control
station 18, and serves to monitor and/or update parameters of those vehicle
subsystems of a particular type. For example, an exemplary service provider
application program 74 may operate to set the engine parameters within
certain ones of the fleet vehicles produced by a particular engine
manufacturer. Similarly, another service provider application program
may be responsible for monitoring the performance of braking systems from
a given manufacturer used within a given set of fleet vehicles. Exemplary
formats for packet header information to accompany message packets
generated by service provider application program(s) 74 are described in
further detail below.
In accordance with one aspect of the invention, these operations are
facilitated by allowing free-formatted data packets to be routed to computers
in service provider control stations by incorporating identifying
information within the packets. In particular, free-formatted data packets
are routed to the appropriate service provider computer by matching device
and manufacturer information within the data packet to a particular service
provider. In the preferred embodiment, the central control station
computer specifies this optional routing operation for data packets
associated with a specified set of the devices connected to each vehicle MCT.
Specifically, the central control station computer sends the MCT a list of the
set of devices selected for the optional packet routing procedure, and also
sends the appropriate VMRS routing codes for each device. In turn, the
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MCT incorporates the appropriate routing information in the packet
headers of messages originating from the selected devices. After being
transmitted by the MCT, these packets are routed by the NMC 24 to
appropriate service provider control stations in accordance with the packet
header information of each. Alternately, the NMC may maintain a separate
database of routing information and thereby obviate the need for routing
information to be provided in the packet header.
In an exemplary implementation, the computers within both central
and service provider control stations execute a log-on sequence upon
becoming connected to the NMC. The NMC is configured in the exemplary
implementation to distinguish between various service provider and
control station computers by examining certain account information used in
the log-on sequence. Service provider accounts may be associated with one
or more MID/VMRS pairs, each of which is associated with a particular
device ID and manufacturer. In this regard the NMC maintains a database
of the various MID/VMRS pairs associated with each service provider
account number. When the above-described optional packet routing is
selected, the NMC routes return data packets received from vehicle
subsystems to the service provider computer corresponding to the MID and
VMRS fields specified within the header of the return packet. Similarly,
only those forward packets with MID and VMRS header information
matching the service provider computer from which the forward packet
originated are allowed by the NMC to be sent to the indicated vehicle
subsystem. In an alternate approach, the NMC is specifically configured to
retain authorization information identifying a predefined set of vehicle
MCT's which may be sent forward packets from a given service provider
computer.
Referring now to TABLE II, a data record included within the vehicle
database 72 stored within the central control station 18 is seen to include an
exemplary set of six data fields. In particular, the Vehicle ID field will
typically include an alphanumeric entry representative of a specific vehicle
within a given vehicle fleet. Since in an exemplary implementation the
header of message packets sent and received by the messaging program
includes an MCT Serial # rather than a Vehicle ID, a separate table listing
the Vehicle ID associated with each MCT Serial # will typically also be
maintained within the vehicle database 72. Accordingly, the terms MCT
Serial # and Vehicle ID, may be used interchangeably hereinafter. Each of
the remaining fields in TABLE II correspond to a field within TABLE I of the
same name.
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TABLE II
Vehicle ID Component VMRS Model Serial Software
(MID) Number Number Version
Number
Referring now to TABLES III, IV and V, there are shown data records
of the type which may be included within data tables stored within the NMC
database 82 of the network management center 24. TABLE ITI specifies a
record including a type of vehicle component (MID) and associated
manufacturer (VMRS) to be monitored and/or controlled by a particular
service provider (Service Provider Acct. #) from the service provider
control station (FIG. 3). As an example, a particular record within TABLE III
could indicate that a given service provider account (Service Provider Acct.
#) would have responsibility for operation of all vehicle engines (MID)
manufactured by the Detroit Diesel Co (VMRS). The NMC may also include
a database of records of the type specified in TABLE IV, each of which
associates a given MCT with one more MID and VMRS combinations for
routing purposes. Each data record of the type shown in TABLE IV, in
conjunction with information of the type included within TABLE III, allows
the NMC to determine the manner in which messages originating in the
ECUs of various types (i.e., of various MID / VMRS combinations) are to be
routed to the processing resources associated with specific service provider
accounts. Alternately, the NMC may include a database of records of the
type shown in TABLE V, in which each MID for each MCT is listed as being
associated with a given service provider. A database of records of the type
shown in TABLE V provides flexibility in that for each MCT having
multiple MIDs associated therewith that the MIDs may be administered by
the same service provider or by different service providers as indicated by
the records for the MCT. Thus a distinct service provider may be specified
for any MID on a vehicle.
TABLE III
Service Provider Acct. # MID VMRS
TABLE IV
MCT Serial # MID V M R S
TABLE V
MCT Serial # MID Service Provider Acct. #
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The data tables within the NMC database 82 primarily serve to ensure
that only parameter information in the appropriate format is relayed to the
specified vehicle subsystem. For example, upon receiving a message packet
generated by a service provider application program 74, a message
verification routine 86 within the network management center 24 will
compare the header of the message packet to the appropriate record (see, e.g.,
TABLE III) within the NMC database 82. Only if information within the
Component and VMRS fields stored within the record for the service
provider (Service Provider Acct. #) match the information within
corresponding fields of the packet header will the message packet be
forwarded by the network management center 24 to the designated mobile
communications terminal. If the information within corresponding fields
does not match, the message verification routine transmits an error message
to the service provider control station 28. Within the control station 28,
messaging program 60' may route the error message to display device 70' in
order that an operator may be alerted to the existence of the error condition.
In an exemplary embodiment the network management center 24
includes a general purpose computer through which the data tables within
the NMC database 82 may be directly accessed and updated. Alternately,
these tables are updated using message packets transmitted to the network
management center 24 from the central control station 18 or service
provider control station 28.
Turning now to FIG. 4, there are illustratively represented a set of
three fleet vehicles 102 - 104 administered by fleet operator control or base
stations 105 - 106, as well as by service provider, i.e., original equipment
manufacturer (OEM) control or base stations 107 - 110. A network
management center (NMC) 110 and an Earth station (not shown) facilitates
communication between each of the base stations and the fleet vehicles 102 -
104. The representation of FIG. 4 is intended to demonstrate the manner in
which the communication system of the invention facilitates management
and administration of a vehicle fleet by more than a single entity. Referring
to FIG. 4, the vehicles 102 and 103 are seen to comprise first (V1) and second
(V2) vehicles within the fleet managed by a first fleet operator (Cl) through
fleet operator base station 105. Vehicle 104 constitutes the first (V1)
vehicle
within the fleet administered by a second fleet operator (C2) through fleet
operator base station 106. Even though the MCTs 111 and 114 respectively of
vehicles 102 and 103 are disposed to communicate only with base
station 105, and the MCT 117 of vehicle 104 communicates only with base
station 106, the messaging protocol of the present invention enables separate
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communication to occur between the subsystems within the vehicles 102 -
104 and the different OEMs, OEMs A-D, through the respective OEM base
stations 107 - 110.
More specifically, vehicle 102 includes an MCT 111 and two vehicle
5 subsystems 112 - 113. In vehicle 102, subsystem 112 is a type unit Al (e.g.,
an
engine) manufactured by OEM A, which is assumed to operate in
conjunction with OEM A base station 107. Vehicle 102 also includes a
subsystem 113 which is a type unit AN (e.g., a brake system) also
manufactured by OEM A. Similarly, vehicle 103 may include a
10 subsystem 116 which is a type of engine (unit A2) also produced by OEM A.
By sending message packets identified by header information in the above-
described format, OEM A base station 107 may send requests via NMC 110 to
the MCTs 111 and 114 of vehicles 102 and 103 that various modifications or
adjustments be made to the parameter settings of one or more of
15 subsystems 112 (unit Al), 113 (unit AN) and 116 (unit A2). In a converse
communication operation, the current configuration or parameter settings
of subsystems 112 (unit Al), 113 (unit AN) and 116 (unit A2) are reported to
OEM base station A via message packets transmitted in the reverse direction
through NMC 110. Similarly, OEM B base station 108 may send requests via
20 NMC 110 to the MCTs 111 and 114 of vehicles 102 and 103 that various
modifications or adjustments be made to the parameter settings of
subsystems 112 (unit Al). Similar messaging may occur between, for
example, OEM C and D base stations 109 and 110 and the respective
subsystems 118 and 119 (units C2 and D1), respectively, within vehicle 104
via MCT 117 and NMC 110.
V. Free-Formatted Data Display
The system of the invention utilizes the free-formatted information
transfer characteristic of the J1587 protocol to facilitate transmission of
ECU-specific or proprietary information to an external display associated
with an MCT. In particular, the central base station is operative to transmit
message packets to the MCTs of selected vehicles identifying which of the
ECUs connected to each vehicle's data link are authorized to use the display
device 33 (FIG. 2) of the vehicle's MCT. The MCT of each vehicle receives
free-formatted data via the bus interface 35 from authorized ECUs, and
transmits the data via the user interface 36 to the external display device
33.
The display device 33 allows a vehicle driver or other user to view
proprietary information received from the ECU of a given device coupled to
the data link.
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Although the central base station may authorize, for example, via an
over-the-air communication, a vehicle MCT to enable its display device to
be used for display of information within message packets from specified
ECUs, it should be understood that other methods of authorization are
within the scope of the present invention. For example, the vehicle MCT
may be configured to locally receive authorization, via user interface 36, to
display information within packets from particular ECUs. It should also be
understood that the displayed information may constitute only a subset of
that transmitted to the base station. For example, it is unnecessary to
display
subsystem identification information or vehicle identification information
at the vehicle itself, but such information is typically included within
transmitted message packets. Furthermore, the displayed information may
be different from that which is transmitted. For example the transmitted
information may comprise event log data or historical data, typically in
binary form, while the displayed information may be advisory in nature,
typically in a readable form such as ASCII text, which may or may not be
related to the transmitted information.
VI. Vehicle Parameter Monitoring
As discussed above, the system of the invention allows the
parameters associated with devices coupled to vehicle data links to be
monitored using the interrogative requests specified by SAE J1587.
Alternately, each vehicle MCT may be configured to use communication
protocols unique to the ECU of each vehicle device during the monitoring
process. In either implementation, the central base station will typically
designate those vehicle devices and subsystems to be monitored by way of a
message received by the satellite interface 37. Upon the occurrence of a
predefined event (e.g., engine start), the parameter monitor 40 queries each
designated subsystem or device coupled to the data link as to the current
state(s) or value(s) of the parameter(s) to be monitored. A parameter
database of the monitored parameters is maintained within the parameter
monitor 40, and through communication with the central base station via
satellite interface 37 allows for all or part of the parameter database to be
replicated therein. TABLE VI provides a representation of an exemplary
3-field record of a type typically included within the parameter database.
TABLE VI
Component (MID) Parameter Current Parameter
Identifier Value
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Referring to TABLE VI, the unique message identifier associated with
a given ECU is stored within the Component field. The Parameter Identifier
field specifies the parameter associated with the specified MID which is to be
monitored, and typically holds a parameter identification character (PID)
specified by SAE J1587. In addition, the Current Parameter Value field stores
the last reported value of the parameter specified in the Parameter Identifier
field. In the exemplary embodiment, following each update of the Current
Parameter Value the MCT sends (via the NMC 24) message packet(s) to one
or more base station(s) indicating its most current value.
The previous description of the preferred embodiments is provided
to enable any person skilled in the art to make or use the present invention.
The various modifications to these embodiments will be readily apparent to
those skilled in the art, and the generic principles defined herein may be
applied to other embodiments without the use of the inventive faculty.
Thus, the present invention is not intended to be limited to the
embodiments shown herein but is to be accorded the widest scope consistent
with the principles and novel features disclosed herein.
WE CLAIM:
