PCT
`
`International Bureau
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`
`
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`
`(11) International Publication Number:
`(51) International Patent Classification 5 :
`
`3 March 1994 (03.03.94)
`G06F 13/00, 15/20
`(43) International Publication Date:
`
`
`
`WO 94/04975
`
`
`
`
`(21) International Application Number:
`
`PCT/US93/07500
`
`(22) International Filing Date:
`
`9 August 1993 (09.08.93)
`
`(81) Designated States: AU, BR, CA, KR, European patent
`(AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU,
`MC, NL, PT, SE).
`
`I;
`
`(30) Priority data:
`930,158
`
`14 August 1992 (l4.08.92)
`
`US
`
`
`
`Published
`With international search report.
`With amended claims.
`
`(71) Applicant: VORAD SAFETY SYSTEMS, INC. [US/US];
`10802 Willow Court, San Diego, CA 92127 (US).
`
`
`
`; 16571 Corte Paulina, Poway,
`(72) Inventors: WOLL, Jerry, D.
`CA 92064 (US). WOLL, Bryan, D.
`; 2 Flamingo Court,
`Laguna Niguel, CA 92677 (US). MALAN, Van, R.
`;
`3250 Via Marin, #3, La Jolla, CA 92037 (US).
`
`(74) Agents: LAND, John et al.; Spensley Horn Jubas & Lubitz,
`1880 Century Park East, Suite 500, Los Angeles, CA
`90067 (US).
`
`(54) Title: RECORDING OF OPERATIONAL EVENTS IN AN AUTOMOTIVE VEHICLE
`
`
`
`
`
`
`DIGIIAL
`SIGNAL
`PROCESSOR
`
`I RECEIVER I
`II
`
`I
`
`
`
`MODULATION
`
`AM.) 1-_ PRDGPEPRABLE
`"”°R°‘
`
`
`I we ARRAY I °°""‘°“ER
`
`mine
`
`
`
`
`
`
`Even
`RECORDING
`APPARATUS
`
`DISPLAY
`ACIUATORS
`
`SENSORS
`
`VEHCLE
`
`(57) Abstract
`
`An apparatus and method for recording operational events in an automotive radar system (1). The invention provides an
`Event Recording Apparatus (ERA) (5) that records selectable vehicle performance, operational status, and/or environment infor-
`mation, including information useful for accident analysis and updated software for use by a system processor (22) capable of
`reading data from the ERA (5). The preferred embodiment of the ERA (5) comprises a non-volatile solid-state memory card (20),
`a memory card adapter (21) located in a vehicle, and a microprocessor (22), either as part of the memory card (20) or embedded
`in a system Within the vehicle, for controlling the storage of data within the memory card (20).
`
`
`Page 000744
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`

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`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PC!‘ on the front pages of pamphlets publishing international
`applications under the PCT.
`
`Finland
`
`France
`Gabon
`United Kingdom
`Guinea
`Greece
`Hungary
`Ireland
`Italy
`Japan
`Democratic People's Republic
`of Korea
`Republic of Korea
`Kazakhstan
`Liechtenstein
`Sri lanka
`Luxembourg
`latvia
`Monaco
`Madagascar
`Mali
`Mongolia
`
`A1‘
`AU
`BB
`BE
`BF‘
`BC
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`Cl
`CM
`CN
`CS
`CZ
`DE
`DK
`BS
`Fl
`
`Austria
`Australia
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`Cate d‘lvoire
`Cameroon
`China
`Ctechoslovakia
`Czech Republic
`Germany
`Denmark
`Spain
`
`Mauritania
`Malawi
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Slovenia
`Slovak Republic
`Senegal
`Chad
`Togo
`Ukraine
`United States of America
`Uzbekistan
`Vict Nam
`
`'
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`Page 000745
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`

`
`WO 94/04975
`
`PCI‘/US93/07500
`
`RECORDING OF OPERATIONAL EVENTS IN AN AUTOMOTIVE
`
`VEHICLE
`
`BACKGROUND OF THE INVENTION
`
`Field of the Invention
`
`This invention relates to automotive radar systems,
`
`and more particularly to an apparatus and method for
`
`recording operational events in an automotive radar
`
`system.
`
`Description of Related Art
`
`In the automotive field, a number of electronic
`
`devices exist that record data on various aspects of
`
`vehicle performance and/or environment information.
`
`such devices have used magnetic tape and paper strips
`
`to record such information. These devices primarily
`
`function as trip monitors, storing information such as
`
`trip distance, trip time, miles per gallon consumed,
`
`and average speed.
`
`A drawback of such devices is that magnetic tapes
`
`and paper strips are susceptible to the detrimental
`
`effects of heat and vibration commonly found in an
`automotive environment.
`A further drawback is that
`
`prior art automotive recording devices have not been
`
`used in conjunction with an automotive radar system to
`
`record such information as the closing rate (CR)
`
`‘
`
`between the recording vehicle and targets located by
`
`the vehicle's radar system,
`
`the distance (D) between
`
`the recording vehicle and targets, vehicle speed (vs),
`
`and such vehicle performance and environment
`
`information as braking pressure, vehicle acceleration
`
`or deceleration in one or more dimensions, rate of
`
`turning of the vehicle, steering angle, hazard levels
`
`determined from a radar system processor, target
`
`direction, and cruise control status,
`
`to name a few.
`
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`

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`\NK)94/04975
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`PCT/US93/07500
`
`2.
`
`Further, it is believed that such automotive
`
`recording devices have not been used to record informa-
`tion to be used for accident reconstruction.
`
`Most commercial aircraft and some private aircraft
`
`are equipped with an event recording device commonly
`called a "black box".
`
`This device records pertinent
`
`data from the aircraft's major subsystems as the
`
`aircraft is operating.
`
`If an accident occurs,
`
`the
`
`"black box" generally can be retrieved from the
`
`aircraft and the recorded information extracted to
`
`determine the status of subsystems of the aircraft just
`before the accident.
`Such information is then used to
`
`reconstruct the events leading up to the accident, and
`can help determine the cause of the accident. Black
`
`box recording devices have proven invaluable in
`
`aircraft accident reconstruction. However, this type
`
`of technology is quite expensive, and its use has been
`
`limited to more expensive vehicles such as aircraft.
`
`In addition, it is believed that all such devices
`
`operate using a cumbersome magnetic tape to record
`data.
`
`These devices also tend to be larger, heavier,
`
`and consume more power than would be acceptable for
`automotive use.
`
`In the area of automobile accident reconstruction,
`
`an accident analyst determines how an accident most
`
`probably occurred by measuring, among other things,
`
`the
`
`length of skid marks,
`
`the extent of vehicle and nearby
`
`property damage, and the condition of the road at the
`
`time of the accident. This method of reconstructing
`
`accidents has been shown to be expensive and inaccurate
`
`at times. Accordingly, it would be desirable for
`
`automotive vehicles to have a system that would
`
`function as an event recording "black box".
`
`Such a
`
`system should record information relating to the
`
`vehicle and the environment around the vehicle prior to
`an accident.
`Such data should be readable after an
`
`accident for use in reconstructing the events leading
`
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`W0 94/04975
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`PCP/US93/07500
`
`3
`
`up to the accident.
`
`An accident could then be
`
`reconstructed using real historical data, as opposed to
`
`post—accident estimated data.
`
`In addition to recording data useful for accident
`
`reconstruction, it would also be desirable for such a
`
`device to record more standard vehicle performance,
`
`operational status, and/or environment data.
`
`In
`
`addition, it would be desirable that such a device he
`
`10
`
`15
`
`configurable for a driver's particular preferences, or
`
`to provide an authorization function that prohibits
`
`unauthorized personnel from driving the vehicle, and/or
`
`to provide a convenient means for upgrading system—wide
`software for an automotive electronic control system or
`an automotive radar system.
`
`The present invention meets these objects and
`
`provides an advance over the prior art.
`
`SUMMARY OF THE INVENTION
`
`The preferred embodiment of the present invention
`
`‘Z0
`
`is particularly well-adapted to be used in conjunction
`
`with an automotive radar system.
`
`The invention
`
`provides a removable, externally readable, non-volatile
`
`solid-state memory Event Recording Apparatus (ERA) that
`
`records selectable vehicle performance, operational
`
`In particular,
`status, and/or environment information.
`the ERA records information useful for accident
`
`analysis.
`
`In addition,
`
`the preferred embodiment of the
`
`present invention can be used to store updated software
`
`for use by a system processor capable of reading data
`from the ERA.
`
`More particularly,
`
`the preferred embodiment of the
`
`inventive ERA comprises a non-volatile solid-state
`
`memory card, a memory card adapter located in a
`
`vehicle, and a microprocessor, either as part of the
`
`memory card or embedded in a system within the vehicle,
`
`for controlling the storage of data within the memory
`
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`

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`PCT/US93/07500
`
`4
`
`card.
`
`The ERA system is configured to store such
`
`vehicle information as, for example,
`
`the closing rate
`
`(CR) between the recording vehicle and targets located
`
`by the vehicle's radar system,
`
`the distance (D) between
`
`the recording vehicle and targets, vehicle speed (VS),
`
`and such vehicle performance and environment informa-
`
`tion as braking pressure, vehicle acceleration or
`
`deceleration in one or more dimensions, rate of turning
`
`of the vehicle, steering angle, hazard levels deter-
`
`mined from a radar system processor, target direction,
`
`cruise control status, vehicle engine RPM, brake
`
`temperature, brake line hydraulic pressure, windshield
`wiper status (to determine if it is raining),
`fog light
`
`status, defroster status, and geographic positioning
`
`information (e.g.,
`
`from a global positioning system).
`
`In addition,
`
`the ERA can be configured to function as a
`
`common trip monitor, recording such information as
`
`distance travelled, average speed, miles-per-gallon,
`
`fuel remaining, compass direction of travel, etc.
`
`The
`
`device can also record vehicle maintenance information,
`
`such as coolant temperature, oil temperature, engine
`
`temperature,
`
`transmission fluid temperature, engine
`
`timing, and more.
`
`The details of the preferred embodiment of the
`
`present invention are set forth in the accompanying
`Once the details
`
`drawings and the description below.
`numerous additional
`
`of the invention are known,
`
`enhancements and changes will become obvious to one
`skilled in the art.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIGURE 1 is an overall block diagram showing the
`
`invention being used in conjunction with an automotive
`
`radar system using digital signal processing.
`
`FIGURE 2 is a block diagram of a RAM card in
`
`accordance with the present invention,
`
`shown connected
`
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`
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`
`5
`
`to the radar system microcontroller and a non-volatile
`
`memory device.
`
`FIGURE 3 is a timing diagram of a Write cycle to a
`
`RAM card in accordance with the present invention.
`
`FIGURE 4 is a timing diagram of a Read cycle from a
`
`RAM card in accordance with the present invention.
`
`FIGURE 5 is a detailed block diagram of a RAM card
`
`in accordance with the present invention.
`
`FIGURE 6 ia a block diagram of an interface between
`
`10
`
`a RAM card in accordance with the present invention and
`
`a personal computer.
`
`I
`
`Like reference numbers and designations in the
`
`various drawings refer to like elements.
`
`15
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`Throughout this description,
`
`the preferred
`
`embodiment and examples shown should be considered as
`
`exemplars, rather than limitations on the present
`invention.
`
`FIGURE 1 is an overall block diagram showing the
`
`invention being used in conjunction with an automotive
`
`radar system using digital signal processing.
`
`Such a
`
`system is described in greater detail in co-pending
`
`U.S. Patent Application Serial No. 07/930,066, entitled
`
`MULTIFREQUENCY, MULTI-TARGET AUTOMOTIVE RADAR SYSTEM
`
`USING DIGITAL SIGNAL PROCESSING and assigned to the
`
`assignee of the present invention. This radar system
`the
`
`is referenced by way of example. However,
`
`invention could be readily adapted to be used in
`
`conjunction with other automotive radar systems known
`
`in the art, such as the systems described in U.S.
`
`Patent No. 4,673,937, entitled AUTOMOTIVE COLLISION
`
`AVOIDANCE AND/OR AIR BAG DEPLOYMENT RADAR, and U.S.
`Patent NO. 4,916,450, entitled RADAR SYSTEM FOR HEADWAY
`
`CONTROL OF A VEHICLE, both of which are assigned to the
`
`assignee of the present invention.
`
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`

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`
`PCT/US93/07500
`
`6
`
`Using the present ERA invention in conjunction with
`
`such a radar system allows recording of important data
`
`relating to obstacles in the path of the vehicle that
`
`were detected by the radar system. This type of
`
`information is particularly useful in accident
`reconstruction.
`
`Referring to FIGURE 1, a receiver/transmitter
`
`module 1 transmits a Doppler radar signal from a radar
`
`transmitter 1a via a radar antenna lb, and receives
`
`reflected radar echoes in a receiver lc through the
`
`antenna 1b.
`
`A control module 2 coupled to the
`
`receiver/transmitter module 1 contains a modulation and
`
`timing circuit 2a that controls the transmission of the
`
`Doppler radar beam, and an A/D converter 2b for
`
`converting the received echo signal into a digital data
`
`stream.
`
`A signal processing module 3 includes a
`
`digital signal processor (DSP) 3a, a microcontroller
`
`3b, and a field programmable gate array 3c, configured
`to control the flow of digital radar data to the DSP 3a
`The
`under the control of the microcontroller 3b.
`
`signal processing module 3 is also coupled to an
`
`input/output module 4.
`
`The input/output module 4 which provides
`
`information from a variety of vehicle sensors 4a to the
`
`microcontroller 3b for use in calculating the hazard
`
`level presented by targets indicated from the received
`
`radar signal and/or to indicate the operational status
`
`and environment of the vehicle.
`
`Commonly known sensors
`
`may be used, for example, to measure vehicle speed,
`
`engine temperature, oil pressure, engine RPM, oil
`
`temperature,
`
`transmission fluid temperature, coolant
`
`temperature, and other values relating to the
`
`environment or performance of the vehicle.
`
`The signal
`
`processing unit 3 itself generates information from the
`
`transmitted and received radar signal, such as the
`
`closing rate (CR) of a target with respect to the
`
`vehicle,
`
`the distance (D) of various targets, and the
`
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`7
`
`direction of movement (towards or away from) of the
`
`targets with respect to the vehicle. Additional
`
`information can be obtained by providing other sensors,
`
`such as a brake pedal pressure sensor, brake hydraulic
`
`line pressure sensor, tire pressure, accelerometer
`
`sensors (for example, fore and aft accelera-
`
`tion/deceleration, and/or left and right (yaw)
`
`acceleration of the vehicle),
`
`turning rate,
`
`turn angle,
`
`and/or impact sensors (such as the type used to trigger
`
`vehicle air bags), windshield wiper status (to
`
`determine if it is raining), fog light status,i
`
`defroster status, and geographic positioning
`
`information. Recording some or all of this data or
`similar relevant data would make accident
`
`reconstruction more reliable and less expensive.
`
`The input/output module 4 also has a display and/or
`
`actuators 4b, for displaying indications to a user
`
`and/or controlling various aspects of vehicle operation
`
`(for example, flashing a dashboard warning light to a
`
`user if a vehicle is approaching too rapidly,
`
`and/or,
`
`in extreme conditions, automatically activating the
`
`vehicle brakes and/or air bag).
`
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`
`Also coupled to the microcontroller 3b is an Event
`
`Recording Apparatus (ERA) 5, described more fully
`below.
`
`25
`
`FIGURE 2 shows a more detailed block diagram of the
`
`preferred embodiment of the present ERA invention,
`
`showing a RAM card 20 coupled through an interface
`
`receptacle 21 to a microcontroller 22 (which may be the
`
`microcontroller 3b shown in FIGURE 1, but can be an
`
`independent microcontroller coupled to the
`
`microcontroller 3b).
`In the preferred embodiment,
`The
`microcontroller 22 includes a real-time clock.
`
`the
`
`microcontroller 22 is also coupled to a non-volatile
`"Non—volatile" means that the data
`
`memory device 23.
`stored in the memnrv device ?1 will be retained even if
`
`30
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`
`power is interrupted to the device.
`
`In the preferred
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`8
`
`embodiment,
`
`the memory device 23 is a "flash"
`
`programmable memory device available from a number of
`
`suppliers.
`
`Such devices are electrically alterable,
`
`but retain their data even after power is removed from
`
`the device. Alternatively,
`
`the memory device 23 may
`
`comprise, for example, dynamic RAM with a battery
`
`backup and refresh circuitry, static RAM with a battery
`
`backup, electrically alterable read—only memory, or
`
`other solid—state, non-volatile memory technologies
`known in the art.
`
`10
`
`The microcontroller 22 and non-volatile memory
`
`device 23 are coupled in known fashion by Address and
`
`Data buses, and read/write control lines FLASHWP, RD,
`
`WR:
`
`as shown, such that the microcontroller 22 can read
`
`data from,
`
`and write data to,
`
`the non-volatile memory
`
`device 23.
`
`The memory device 23 is preferably used to
`
`store programs to be executed by the microcontroller 22
`of the
`
`for control of all, or various aspects,
`
`components shown in FIGURE 1.
`
`In the preferred embodiment,
`
`the interface between
`
`the RAM card receptacle 21 and the microcontroller 22
`
`is kept as simple as possible. Preferably, a standard
`3—wire (not including power and ground) serial
`interface bus is used, which has a clock line CLK for
`
`the data transfer clock, a DQ line bidirectional data
`
`line, and an REE line to enable/disable the RAM card
`
`The 3—wire bus is coupled to the microcontroller
`20.
`22 as shown.
`
`An advantage of the simple 3—wire serial interface
`
`bus preferred for use with the present invention is
`
`that it is well known, simple to implement, and
`
`requires a minimum amount of interface connection
`between the RAM card 20 and the microcontroller 22.
`
`However,
`
`other interfaces could be used, such as the
`
`more complete RS232 serial interface standard. As
`
`another alternative,
`
`the RAM card receptacle 21 could
`
`be an adapter compatible with the Personal Computer
`
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`
`9.
`
`Memory Card International Association (PCMCIA)
`
`interface. As yet another alternative, a fiber optic
`
`connection could be used, which would give the system
`
`greater immunity from electromagnetic interference.
`
`The RAM card 20 comprises one or more non-volatile
`
`memory devices and appropriate control and interface
`
`circuitry.
`
`The RAM card 20 may comprise, for example,
`
`dynamic RAM with a battery backup and refresh
`
`circuitry,
`
`static RAM with a battery backup, flash
`
`memory devices,
`
`electrically alterable read-only
`
`memory, or other solid-state, non-volatile memory
`
`technologies known in the art. The data storage
`
`capacity of the RAM card 20 is a matter of design
`
`choice and available integrated circuit chip capacity
`
`and size.
`
`In the illustrated embodiment,
`
`the capacity
`
`of the RAM card 20 is at least 32 kBytes.
`
`The RAM card 20 may be custom designed, or may
`
`be
`
`a commercial product.
`
`In the preferred embodiment of
`
`the present invention,
`
`the RAM card 20 comprises a
`
`model DS6417 "cybercard" from Dallas Semiconductor,
`Inc.
`
`the microcontroller 22
`In the preferred embodiment,
`begins a data transfer to the RAM card 20 by sending a
`
`56-bit protocol word to the RAM card 20. Referring to
`
`FIGURES 3 and 4, all data transfers to and from the RAM
`
`card 20 are initiated by setting the REE input to a
`
`.1ogical "1".
`
`resetting the RET signal to a logical "0".
`
`Each data transfer is terminated by
`In the
`
`preferred embodiment,
`
`the protocol word includes a
`
`command byte,
`
`2 bytes for the starting address where
`
`data storage or retrieval will begin, and a cyclic
`
`redundancy check (CRC) byte or word that ensures all
`
`bits have been transmitted correctly.
`
`After the desired operation (e.g., Read or Write)
`
`is specified by the 56-protocol word, a first byte is
`
`read from or written to the designated address a bit at
`
`a time.
`
`The address is then automatically incremented
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`
`to the next location, and a next byte is read or
`
`written. As desired,
`
`the microcontroller 22 can write
`
`any data from the non-volatile memory device 23 to the
`
`RAM card 20, or vice versa.
`
`5
`
`Referring to FIGURE 3, for a Write cycle to the RAM
`
`card 20,
`
`the data input bits and the command word bits
`
`on the DQ line must be valid during the rising edge of
`
`the clock signal CLK. Referring to FIGURE 3, for a
`
`Read cycle from the RAM card 20, data bits read out of
`
`10
`
`the RAM card 20 must be valid during the falling edge
`
`of the clock signal CLK. When data transfers are
`terminated by the reset of the RET signal,
`the transi-
`tion of the RET signal from a logical "1" to a logical
`
`"0" must occur during a logical "1" state of the clock
`
`15
`
`signal CLK. This simple protocol ensures a generally
`error—free transfer of data to and from the RAM card
`
`20.
`
`FIGURE 5 is a more detailed block diagram of the
`
`RAM card 20 in accordance with the present invention."
`
`20
`
`A serial port buffer 51 serves as the electrical
`
`interface to the preferred 3-wire serial bus shown in
`
`FIGURE 2.
`
`The serial port buffer 51 is coupled to a
`
`serial—to—parallel byte-wide converter 52, which
`
`converts serial data to and from byte—wide parallel
`
`25
`
`data.
`
`The converter 52 responds to the clock signal
`
`CLK and REE input to accept data from or transmit data
`
`to the data line DQ.
`
`The converter 52 also controls a
`
`non-volatile memory 54 through the use of a
`
`data/control buffer 53, as provided by the
`30 manufacturer.
`
`In the illustrated embodiment,
`
`the memory 54 is a
`
`static RAM with sustaining power supplied by a battery
`
`55, permitting the RAM card 20 to be removed from the
`
`RAM card receptacle 21.
`
`The battery backup also
`
`35
`
`protects against data loss if the power from the RAM
`
`card receptacle 21 is interrupted due to system failure
`or an accident.
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`If fixed-size data blocks are used, data stored in
`
`the memory 54 is delimited by an implicit block size.
`
`If variable-size data blocks are used,
`
`the data
`
`preferably contain internal record and field length
`
`counts and/or unique delimiters, so that the blocks can
`
`Such variable-
`be read back in a meaningful manner.
`size record structures are well-known in the art.
`
`However, for simplicity of implementation,
`
`the
`
`preferred embodiment of the invention uses fixed—size
`data blocks.
`
`10
`
`15
`
`20
`
`In operation, a RAM card 20 would be inserted into
`
`the RAM card receptacle 21.
`
`In the preferred
`
`embodiment,
`
`selected data would be gathered from the
`
`vehicle sensors 4a and/or the signal processing module
`
`3 by the microcontroller 22, typically after the
`vehicle is started.
`The data is stored into the RAM
`
`card 20 by the microcontroller 22 at periodic
`
`intervals, which may be determined by time and/or by
`
`distance traveled.
`
`The microcontroller 22 may also do
`
`some computation on the data, such as determining a
`
`miles-per—ga1lon value or average speed,
`
`to derive
`
`processed data for storage in the RAM card 20.
`
`In general, data blocks would be stored in the RAM
`
`25
`
`card 20 beginning at the first location in the memory
`54.
`
`The address is incremented to point to successive
`
`storage locations for storing subsequent data blocks.
`
`Different modes of operation can be used.
`
`In a
`
`first mode, selected data is stored approximately every
`
`0.5 seconds, until the memory 54 on the RAM card 20 is
`
`full (which,
`
`in the illustrated embodiment,
`
`takes about
`
`15 minutes).
`
`Thereafter,
`
`the address sent to the RAM
`
`card 20 by the microcontroller 22 is reset to the first
`
`address used, causing the oldest data in the memory 54
`
`to be overwritten with new data (i.e., the memory 54 is
`
`operated as a circular queue). This provides a "moving
`
`window" of the last 15 minutes of operation (or longer,
`
`if longer intervals or a larger capacity memory 54 are
`
`30
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`used). Recording can be stopped when external power to
`
`the RAM card 20 is turned off (for example, when the
`
`vehicle is turned off voluntarily or because of an
`
`accident), or when the vehicle is not moving.
`
`If
`
`5
`
`desired, a delayed turn-off time can be used to
`
`continue recording for some period of time after
`
`external power is removed,
`
`to record, for example, such
`
`things as the engine coolant temperature as a measure
`
`of residual heat in the engine.
`
`10
`
`In a second mode of operation,
`
`the memory 54 is
`
`divided,
`
`in a static or dynamic fashion,
`
`into multiple
`
`logical_"pages" for storing independent sets of data.
`
`A "current" page may be used to record a moving window
`
`of, for example, selected data from the last 5 or 10
`
`15 minutes of operation, as described above for the first
`
`mode of operation.
`
`one or more additional pages can be
`
`used to record, for example, selected data (which need
`
`not be the same items of data stored in the current
`
`page) for fixed or variable time periods for later
`
`20
`
`Such data may include, for example,
`analysis.
`information related to vehicle maintenance.
`In such a
`
`case, when a page fills up, writing stops,
`
`in order to
`
`preserve an archival record of the selected data.
`
`A
`
`page would be "reset" after a read-out of the data or
`
`25
`
`upon execution of a specific command, permitting new
`
`data to be written to the page.
`
`In one variation of the second mode of operation, a
`
`first page may be used to record a moving window of
`
`selected data.
`
`If an accident occurs,
`
`the first page
`
`30
`
`of data is "frozen", and a next page is used for
`
`subsequent recording. An accident condition may be
`
`detected automatically, or indicated by activation of a
`
`manual switch.
`
`In this manner, data can be captured
`
`for later analysis of the accident.
`In another variation of the second mode of
`
`35
`
`operation, recording to a page other than the current
`
`page may be triggered by an unusual event, such as a
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`vehicle operational or performance value exceeding a
`
`preset threshold value, or an accident.
`
`For instance,
`
`it may be desirable to record drive train sensor values
`
`only if one or more values, such as engine temperature,
`
`exceed a threshold value. As another example, such
`
`recording may be triggered by an unusual condition that
`
`may indicate an accident, such as a sudden acceleration
`
`or deceleration, sudden application of the brakes,
`
`activation of an air bag, etc. Recording can also be
`
`triggered manually. Recording such information on a
`
`separate page in memory, and only upon being triggered
`
`by a particular event, permits capturing data for later
`
`analysis of vehicle and/or driver performance.
`
`In a third mode of operation,
`
`the recording rate
`
`may be increased upon the occurrence of an unusual
`
`condition, such as a sudden acceleration or
`
`deceleration, sudden application of the brakes,
`in order to store more
`
`activation of an air bag, etc.,
`
`data values surrounding the event, for later analysis.
`
`One skilled in the art would recognize that
`
`variations and combinations of these modes of operation
`
`could be implemented with the present invention as a
`
`matter of design choice.
`
`The selected data may be any of the values
`
`mentioned above, or similar values. Further, not all
`of the values selected need be recorded at the same
`
`10
`
`15
`
`20
`
`25
`
`rate.
`
`For example,
`
`information that can change
`
`rapidly, such as the status of the brake system,
`
`turning conditions, and other
`vehicle speed,
`information useful for accident reconstruction
`
`30
`
`purposes, may be recorded very frequently (e.g., every
`
`0.2 seconds).
`
`Information that changes more slowly, or
`
`is less pertinent to accident reconstruction, such as
`
`engine temperature, coolant temperature, etc., may be
`
`35
`
`recorded less frequently (e.g., every 5 seconds, or
`
`every mile).
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`To read out the data collected in the RAM card 20,
`
`the RAM card 20 is removed from the interface
`
`receptacle on the automotive system and inserted in a
`
`similar interface coupled to a personal computer.
`
`The
`
`5
`
`data can then be displayed on the computer or stored on
`
`a different memory device, such as a floppy disk or a
`
`hard drive in the computer.
`
`FIGURE 6 ia a block diagram of an interface between
`
`the RAM card 20 and a personal computer
`
`(PC) 60.
`
`An
`
`10
`
`interface receptacle 21,
`identical to the interface
`receptacle 21 in the vehicle system, is coupled to a
`
`bidirectional connector 61 that is connected to a
`
`parallel port of the PC 60.
`
`The signal lines between
`
`the PC 60 and the RAM card 20 are preferably the
`standard 3—wire serial bus described above.
`The
`
`15
`
`bidirectional connector 61 may also provide a parallel
`
`interface signal pass-through so that a standard
`
`parallel interface device, such as a printer (not
`
`shown), may still be coupled to the PC 60 through the
`
`Such pass-through type connectors are
`20 parallel port.
`well—known in the art.
`
`when a RAM card 20 is removed from a vehicle
`
`system,
`
`the card is inserted into the interface
`
`receptacle 21 for data retrieval by the PC 60. Data is
`then read out of the RAM card 20 under control of the
`
`25
`
`microcomputer of the PC, using the same process
`described above with respect to the microcontroller 22.
`
`That is, data is transmitted serially through the
`
`bidirectional connector 61,
`and to the microcontroller.
`
`through the parallel port
`The microcontroller
`
`30
`
`converts the serial data to parallel form under
`
`software control,
`
`in known fashion.
`
`Once data has been retrieved from the RAM card 20,
`
`it can be displayed on the PC in a variety of ways,
`
`35
`
`such as in various tabular forms, depending on whether
`
`the information represents accident reconstruction
`
`information, trip monitoring information, maintenance
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`information, or other information.
`
`The manner of
`
`presentation of the data is a matter of design choice.
`
`Since the RAM card 20 is removable and relatively
`
`inexpensive, each driver of a particular vehicle, such
`
`as a fleet car or bus, could be given a personalized
`RAM card 20.
`
`the ERA invention can be used to
`
`Thus,
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`monitor the performance of particular drivers,
`
`including characteristics such as average driving
`
`speed, braking and acceleration habits, typical
`
`"headway" distance (i.e., the distance from the vehicle
`
`immediately in front in the same lane, as determined by
`
`the radar system), etc.
`
`As another aspect of the invention,
`
`the ERA can be
`
`used to provide an authorization function that
`
`prohibits unauthorized personnel from driving a
`
`vehicle.
`
`Since each driver can be given a personalized
`
`RAM card 20, each RAM card 20 can be "keyed" with an
`
`electronic "signature" to work only with a particular
`vehicle. Anyone without a RAM card 20 "keyed" to a
`
`vehicle could not drive the vehicle.
`
`The "keying"
`
`signature may be as simple or as sophisticated as
`
`desired, and may be, for instance, a numeric code
`
`stored in the first address of the memory 54 of the RAM
`
`card 20.
`
`A matching code would be stored in the non-
`
`volatile memory device 23.
`
`The microcontroller 22
`
`would read the pre—stored code in the RAM card 20 and
`
`compare the code with the corresponding code read from
`
`the non-volatile memory device 23.
`
`If no match
`
`occurred,
`
`the vehicle would not be enabled to operate.
`
`In addition, each RAM card 20 may have an "expiration"
`
`date coded therein, such that the vehicle would not be
`
`enabled to operate if the card had expired.
`
`As another example,
`
`in order to enforce mandatory
`
`rest stops, a RAM card 20 and microcontroller 22
`
`combination could be programmed to disable the vehicle
`
`for a fixed period of time after a stop, or until an
`
`authorization code was provided by a dispatcher (such a
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`
`code could be provided to the microcontroller 22 by
`
`means of a 10-key keypad, for example).
`
`As another aspect of the invention,
`
`the ERA can be
`
`used to load upgraded or updated computer programs
`
`5
`
`(software)
`
`into the vehicle system.
`
`In this mode of
`
`operation, new software is loaded into a RAM card 20
`
`through, for example, a PC 60, before insertion of the
`
`RAM card 20 into a vehicle system.
`
`The microcontroller
`
`22 in the vehicle system reads the new program data out
`
`10
`
`of the RAM card 20, converts it from serial to parallel
`
`form, and stores it in the non-volatile memory device
`
`23 coupled to the microcontroller 22. The uploaded
`
`software may be for an automotive electronic control
`
`system or an automotive radar system, or both. This
`
`15
`
`feature circumvents the time consuming and cumbersome
`
`task of removing the control system from the vehicle to
`
`load a software upgrade.
`
`This aspect of the invention can also be used to
`
`"customiz