CA1311056C - Vehicle data recording system - Google Patents

Abstract

ABSTRACT
A vehicle data recording system has connections to one or more analog sensors, and stores data from the sensor(s) in a memory during a laps of a track.
The system provides for analog/digital conversion for converting analog data from the sensor(s) into digital data and triggers a procedure for storing of the data in memory. Periods of storing of the data in memory are automatically started and stopped. The system stores in memory a set of data for a datum period and has means for storing further sets of data in a memory. A set of data stored during a first period is compared with a set of data stored during a further period and one of the sets of data is selected for retention in memory in accordance with a predetermined algorithm. The retained set of data is compared with the datum set and differences between the datum set and the selected set are output.

Description

!1~1D~:5~

~E~L ~STF:M

The pre~ent invention relate~ to a vehiole reco~dinq sys~em and, more particl~larly, to an on-board comp~ter deslgned for raciny cars.
In order to provide information to She drlver, engineers etc. of a raeing car team, i~ i~ de~irable to ~ecord data relating to the move~en~, speed, and other operational ~actor~ for subsequent analy~
1~ Accordin~ to the present invention ther~ 18 pravided a vehicle data recording ~y~t~m for connection to one or more analog sensors and for ~toring data f~om the sensor(~) in a memory during a plurality of cbosen periods, the system co~pri~ing:
lS analog/digital conversion mean~. for converting analog data from the sen~or(s) ~nto diyi$~1 data~
~ ean~ for trigqerlng a procedure for storlng of the data lnto memory;
~ eans for auto~atically ~tarting and endln~
~ per~ods of ~oring of the data ln memory;
means for ~to~ing ln memory a set o~ data for a d3tum period;
means for ~toring fu~ther ~et~ of data in a mer~rYt mean~ for co~par~ng a set of data stored during fir8t period ~ith a 8et of data ~tared during a further period and ~electing for ~etention in memory one of the ~e~ of dat~ in accordance with a pred~termined alqori~hm; and, mean~ fo~ Co~par$ng ~ald retained ~et of data with the da~um 8et and ou~putting difference~ bet~en ~ald datum ~et and ~id selected set.
Preferably, the mean8 for ~u$omatically ~tartin~ and ending periods of ~toring of the data in a transmitter for trans~itting a beacon ~ignal;

a receiver for monitorinq for the pre~ence o~
the beacon ~ignal; and, mean~ re~ponsive to the rece~pt o~ the ~ea~on sign~l to indicate the end of one set of data and the ~tart of a further set, The mean~ for tri~gering a procedur~ for ~torlng of the d~ta into memory may include ~ manually operable ~witch a~tu~ble ~y the driver of a vehlcle in ~hich ~he sy~tem is lnstalled.
F~rthermore, the means for displaying the differences between the datum set and the ~elected set may advantaqeously include a printer remo~ably attachable to the ~yste~.
. one exa~ple of a syste~ accordin~ to the invention w~ll now be de~cribed with referen~e to the accompanying drawings, in which:-Fi~ure 1 i6 a diagra~ati~ repre~entation o~the fron~ face of a display/proce~sor unit of the ~y~tem Fiqure 2 i6 ~n example o~ a lap report produced by the system;
Flgures 3A & 3B are dlagrammatlc represent~tion~ of the ~ystem circult and arrangement on a ~arS and, Fi~ure 4 i~ ~ flow diagram of ~he ~ystem ln use.
The electronic dat4 recording ~y~tem ha~ three functlon6. Firstly, it provides all the fa~ilitle~
o~ conven~ional race ~ar da8h mounted instrumention, al~hough w~th added feature~ such a~ memory ~nd automatlc warn$n~. Secondly, ~t can be u~ed a~ a data-logger capable o~ ~torinq large quan~tie~ of ~n~ormation from many different type~ of ~ensors.
~hlrdly, the ~y8tem can produce prlnted ~lap repor~s~
~8 ~oon ax the car ret~rnh to the pit lane. The~e ~erve the purpo~e of quantifyln~ mechani~al change~
ln such a way 80 that the race engineer can ~ee where on the track, and by how mu~h, the c~r ha~ gone 3 131 105`~

q~icker or ~lower after its set ~p has been altered.
The main dlsplay/proce~or unit 100, wh~ch houses most of the electronic components, ~lso has an LCD dl~play 124 which provides the driver with a tachometer 201 and three alphan~er~c dlsplay~
202-20~. A nine-po~ltion rot~ry switch 205 allow~
the u~er to ~witc~ between dlfferent di~pl~y reading~
as required, ~7arnings are automaticall~ issued by the ~y~tem ~B nece~8ary, for ex~mple a drop in oil pressure would trigger an ~larm no m~tter what the display wa~ set to read. such warnings must be acknowledged by the drive~ before the display reverts to lts previou~ reading.
The system can be u~ed to log data continuou~ly on plural independent channels (up to forty channels are possible with an exp~n~ion board added). The data acquired can be o~-loaded fro~ the system to a host pe~onal compuSer. Softw~re ha~ been wr~tten to allow the user to an~lyse data at leisu~e on a per~o~al computer should he ~o wish. The dA~a 18 automat~cally divided into lap~ and ~an be d~splayed graphically. The graph~ obtained ~an be exp~nded and overlaid for comparl on.
The lap report~ provide the race engineer and ~5 the driver with an as~es6ment of the car ~8 pe~for~ance. Thi~ 1~ prl~arily ln terms of speed~
although additional information on rpm, ~008t etc~
may be prov~ded. The reports are pr¢ ented either i~
an ab301ute mann~r or in ~ form wh~ ch compares one lap to anothe~. The purpose of the l~p report i5 to pro~ide the race engineer wiSh immedi~te information giving him ~ deeper in~ight into the manner in whlch enqlneerlng ch~nges on She car have altered the car '~
perfor~ance~ The onu~ 18 no lon~er on the d~iver to ~udge the relat~ve merit~ of different set-up~. The lnstant avail~bility of the neoe~ary lnformation allows ~ore ob~ectiv~ty to be brouyht S4 bear on She ~31 1056 task of optimi~lng the car 18 performance.
In order to enable enhanclng and expanding upon the exi~tlng cap~bili~1e~ of the sy~tem the hardware design of the sy~tem ha~ been implemented to allow for considerable expan~lon of ~oftware ln the fut;ure. Thu~, once the sy~tem ~8 in place any update6 or cu~tomlsaSions to the ~ystem can be lncorp~rated ~imply by changing an EPRO~ 123 (which ~tor~ the ~oftware to control the ~y~em). This is a totally ~tra~ghtforward process. In addition ~t i~
quite fea~ible ~o pl~g ln elect~onically controlled devl ~es ~o that the box cal~ ac~ as ~he 'brain ' of an "active~ system in order to provide ~ctual control of variou~ engine management etc. functions.
Con~ldering the sy~te~n a~ a whole~ the sy~tem offers a complete ln~trumentat~ on and analy~ls ~y~tem wlth in-built power and flexibillty.

The ~yste~ 1~ comprised of a di~pl~y/proce~or unit lO0 complete wlth power ~upply 101 and ~ensor~
~or r.p.m 102, ~peed 103, pr28sure 10~-106, ~empeeature 107rlO8 and the 'beacon ' 109~ a prlnter 110 and a track~lde beac~n lll. The latter two ~tem6 are used by the ~ pit crew~ The d~splay/proce~or unit ~nd its ~en~or peripherals are p~rmanently ~ttached to a car ~, the boost. fuel and oil pre~sure ~en~or~ ~0~-106, the water ~nd oil ~emperature sen~ors 1~,108, the be~on de~ector 109 and printer port 113 all belng conne~ted to the di~play~proce~or unit thro~gh a 81~e box 114 which al~o houses an lnclino~et~r 115. Spare analogue 116 and digital input llne~ ~re pro~ided ~or additional sensors de8ired in a given car, eg. ride height ~ensor, gearbo~ oil temper~ture, thro~tle angle. The ~ain Bystem i5 deslgned to be p~rt of the race car, and no~ an add~on jU8~ for te~t~ng.

s The rpm ~ensor 102 pas~e~ slgnals to an rpm proce~or 120 into which are ~et values to represent the full scale read~ng of rpm permi~c:ible, the number of engine ~ylinders and the 'red line' rpm point.
S All other s~gnal~ from ~ensor~, together with a proces~ed rpm siqnal are fed to a microcomputer 1~1 (ln thi6 example a 'Tattletale V form On~eS Computer Corp.), wh~ ch also h~s connections to an EP~OM 122 and RAM 123.
The display/proce~sor unit 100 i~ hou~ed d~rectly in front of the steerlng wheel and contain~
a ~mall ~creen 200 conslsting of a tachometer 201 and three alphanumeric display~ 202-204 in addition to various other electronic~ component~. On the left hand side of the box i~ a large ~ota~y nine-position ~wiSch 20S which i~ used to sel~ct ~he various facil~tieæ o~ the sy6~em. On the top lefthand corner of the box i~ a push bu~ton 206 Which the driver ~eY
to control the cho~en f~llity, for example to reset 2~ the lap counter to ze~o. On the r~gllthand side of the front f~ce of the box i6 a small rectangular door 207. The EPROM chi~ ituated behlnd this door.
When a full data logging test is required to be carried out an additional log~ing box can be connected into ~he ~ystem via a connector 11~, slgnal~ from it being fed dir~ctly to the d~splay/processor unlt 100. Dependin~ on the configuratlon of the test th~s box may have quite nu~ber ~ ~en~or8 stemmlng from ItE port~, for example, s~r~n ~uages, linear transd~cer~, pro~imi~y sen~or~ which may be used to me2clure ~ccurately characteri8tics of the car 6uch as ~uspension operation, ride height etc.. The main use for ~u~h data logging i~ durlng development of a car.
The logging box 1~ removable from the car ~hen logglng i~ not ~peclflcally ~equired. A ~pecial lead i8 plugged into the display and logging l:~oxe~, connec~ing the two and allowing them to com~unlc,ate.
When the two hoxe~ are connected in this way the drlver or engineer can use the di6play/proce~or unit 100 ~ontrol~ ~o set parameters foc the logglng box.
S In turn, the logg~ng box can send data to th~ dl~pl~y screen. The di6play/proce~or unlt 100 also ha~ four log~ng channel~ o~ itfi own. Thu~ ~vlne da~a logg$ng can be perf~rmed without uslng the logglng box, obviating the need to f~t the logglng bo~ a~ all when perrormlng simple teBt~.

The printer 110 also p:Lug~ lnto the displ~y~proces~or un$t 100 via a printer port 113 and the ~lave box 114 Y~ tuated in t~e ~ide of one of the car '8 sidepods 2. As the car 1 comes to a halt in the pit lane the eng~neer can 6imply plug the printer ~a~le into the car's pr~nter port 113 and the sy~tem will immed~a~ely prlht out a lap repor~:~
An optio~al data buffer/di8play un~t 110' may be ~onne~ted to the printer port ~n place of ~or a~
~hown, in f~ont of) the printer 110, and thi5 includes a RAM to whlch data, wh~ch ~ould normally be outputted by the ~y8tem to the pr~nt~r, can be 8tored temporarily and dl8played/previewed on a liquid cry~tal di~play for in~tant analysl~ o~ resul~. The data can then be output~Rd to the prin~er 110 or to a personal computer for long term ~torage/analysis of the data. The attachment of the buffer/display unit 110' without the printer reduces waltinq time ~t the trackside a~ data can be downlo~ded to the unit ~uch ~ore qulckly than it a~n to ~ prlnter and al~o allows quicker feedback to the drive~ after an~lysis of ~he re~ults on the di~play.
The b~acon 111 i8 placed ~eside the track and transmit~ a ssgnal (whi~h ~n the present example i~
an infra~red signal ~t a frequency of 950 nm, pul~ed at 4kBz and with a 1~ duty cycle) ~hich i8 receiYed by the detector 109 each time the! ear pa~ses the ~ 3 ~ 6 beacon. The detector contain~ an optical band pas~
filtec at 950 nm ~ appro~ 20 nm, a hlgh p~
electrical f~lter ~nd a circuit for de~erm~ning a sequence o~ n pul~e~ for which the ~pa~lng 1~ ~ 2~ of the no~al pulse spacing. Thi~ enables the software from the EP~OM to calculate lap time~ and to dlvide the da~ ~t ha~ acguired inSo segments corre~pondlng to one lap.
A personal computer ~not ~hown) i8 u~ed to analy~e data logged by the logging box (or by the displ~y/proce~sor unlt 100). The computer c~n bé
plugged into the ~ystem vla the printe~ port 113 and the operator then uses the computer to transfer data rom the ~y~tem to the computer. Once tran~ferred in thi~ way the data can be stored permanently on the co~puter'~ hard or floppy di~ks and analy6ed at any t$~.

~0 The ~y~tem lc controlled by the u~er by mean~
of the two 6witche~ 205,206 mo~nted on the di~play/procesYor un~t 100. ~he roti~ry nine-position switch 20S enable~ ~he user to ~elect the varlous ~nstrumentation, lap report and data logging option~, 25 and the pu~h-b~teon switch 206 iB u~ed to set up and control ~hese different optlon~.
Each of the nine pos~t~on of ~he n~ne-po~i~ion swi~ch ~05 corre~pond~ to a function or ~et of functions. When the user 8elect~ a new ~witch po~ltlon the current s~een di~play 1~ cle~red and the screen display~ show a me~sage informing the u~er of the new po8i~ion nu~er. Thi~ me~sage takes the form of the word~ "NOW AT" and the pos~ tion number .
The mes~age iB cle~red a~ter half a second and ~he ~elected d~play appe~rs.
The push-button ~wltch 206 can be used in three way~. Firstly, by pre~sing the ~tton down g 131 1056 momentarily, the user can sither control the function whi~h he ha~ selected, o~, lf he has cho~en a nine-posltlon switch 2~5 settin~ wlth ~ore than one option, ~witch bet~een o; ~elect t;~e f~nction6 in S turn~ Secondly, hôldlng the ~witch down for more than one-and-a-h~lf seconds hut less th~n five seconds perform~ a R~S T. Th~B w~ e~ a glven function to zero, for example ~he lap~counter~ As xoon a~ ~he word ~RES~r" apyear~ in the lefthand ~ext w~ndow 202 the switch may be rqlq~ased. ~hirdly, hold~ng the 3~1tch down for more than fif~een ~econds performs a MASTER RESET. Thi~ allows a f~nda~ental change to be implemented, for example the sy~tem's internal circult ~ap ~an ~e set up for a ne~ race track by performlng such a reset. A~ter the ~witch has ~een held down ~or ~ive ~econds the di~play counts down from ten to ~ero. When the counSdown reache~ z~ro the word ~MASTER~ appears on the d~play followed by the word R~SET~. If the switch i8 releaged before zero 1~ reached (i.e. beore fifteen 6econd~ ha~ elap8ed ~n total ), the sy~tem asR~me~
that nei~her a RESET nor a MASTsR RESET waF: intended and contlnues as if the swl~ch had not been pressed.
For ~ome 8etting8 of the nine-position ~witch 20S
25 RESETS and/or M~5TER RESET~ are inappropriate and depres~lng the pu6h~button switch 206 for extended perlods will have no effect.

3~ The di~play/processor unlt lO0 Bcreen con~ists of an LCD display 1~4 which prov~de~ a tachometer ~01 in the fo~m of a b~r~raph and three alphanumeri~
dlsplays 20~-~04~ ~he tachometer 201 ~s permanently onO The three alphanumer~c diRplay~ are refer r~d to througbout as the main display, the top dlspl~y and the le~thand dl~play aR ~:bo~vn ~n F.ig. 1. These convey lnformation to the user either ln combination with one another or independently depending on ~he ~el.ected function. The user can also if he wishe~
have them remaln blank.

1~ b~A~
Thi~ ~ec~ion de cr~bes the way~ ln whlch the 6y~tem fulflls the funct~n of an in~trumentatlon sy~tem. The bar-graph tachometer 201 ~æ permanently on. The thr~e alphanumeric di plays 202-204 provide lnormation a~ determined by the dr:iv~r'~ uoe of the di~play/proces60r unit switches. The driver can choose to look at variou~ readin~ by selectin~
certain sett~ngs of the nine-position l3witch 205, In ad~tion the sy~tem a~tomatically generates wa~ning~
~hen cr~tical conditlons occur, for e:~ample when the ~ater temperature ri~es to too high a ~.evel~

a~ 1a~ C~p~
The ~creen displ~yæ a stopwat:ch, a timer to time qual~fying se~ions and ~ lap counter. The stopwatch u~a~ the main di8play 203, the lap counter the top display ~04 and the æeEIslon timer the lef~hand dlsplay ~0~.
~he ~topwatch a~tomatically tl~e~ each lap and i~ triggered and re~et by the ~xackside ~eaCon 111.
The lap time, di~pl~yed ln rainute~, ~econds and bundredth~ of a second, i~ updated a~ soon a~ the car pas~e~ the beacon. Thus at any glven tlme the l~p tlme of the prevlous lap i~ shown.
~he lap counter and the tlmer ~xe controlle~
to~ether. Initlally the lefthand d~play 202 show~
the text ~IME~ and the top display ~04 æhows the text ~LAP 0~. One pres8 of the puBh-button ~wit¢h 206 erase~ the ~TIMB~ mess~ge and ~tart~ ~oth the lap counter and timer from zero. The next pre~s of the switch resets them to ~ero and reæt~rtæ them.
Once started the lap counter i~ incremented each ~lme lo 131 1~56 the car pas~es the beacon and the ~e~ion timer count~ the minutes slnce the restart. The lap counter will count up ~o a maximum o~ 9~9 lap~.
A RESET re~et~ both the timer and the lap counter to zero withouS re~tartin~ them. The lnltial text mes~ages ~TI~E~ and ~LAP 0" ~re dl~played. The stopwatch is reset to zero but conSinuea to be tri~gered and rese~ by the beacon~ ~ MASTE~ RESE~ i n this setting o~ the nlne-po~itlon ~wltch 205 wlll ha~e no effeçt.
The l~p counter and the t~mer will both continue to function eYen if the nl~e-po~ition switch 20S is moved f~om position one. Thelr re~pecti~e displays will reappea~ showing their cu~ent values if the nlne-po~ition switch 205 is sub~equently ~urned back to po~ition one.
The initial screen will be seen the fir t time th~t the u~e~ turns to ~witch po~ition one ~fter switching the ~ystem on or performing a MA~ER ~ESET
~Q (when in another swltch position), a~ well a~ after a RES~ perfor~ed ~n ~witch posltion one~

Switch posltion two allows the driver or the 25 race engineer to check the four core readings: water tempera~urer oil temperaSure, oil pre~su~e and fuel pressure (boost in the case of turbo-cllarged cars).
The lefthand di~play 202 re~ds ~WA~ER~ ~
~OIL~ OI~-P-, ~PnEL~ (or ~BOOST~ ) aR
30 appropri~te. The top display 204 ~hows an app~opria~e maximum or minimum reading by which to jud~e the currant readlng. These ~axima and minlma are de~cri~ed below. The m~in di~play show~ the curren~ read~ng in engineering units. The water and oil temperature~ are ~hown in de~ree~ centigrade, the o~l and fuel pre~6u~ in PSI and the boost pre~ure ~n inche~ of ~ercury~

The driver or the engineer c.~n switch between the fol~r reading6 by pre~sing the push-button gwitch 206. Each pre3s of the switch ~elect~ the next readlng in turn, the display ~equence cycling back to w~ter temperature ~fter fuel/boo~t preBsUre.

~ he top di~play ~04 ~hows to the neare~t integ~r the max~mum wate~ temper~tuee in degrees cent~grade 80 ~ar encoun~ered~ When the car ~tops an~ ~e~tart8 the ~aximum 1~ updated to th~ cur~ent reading aft~r one minute to allow for the ri~e in water temperature whilSt the ear was ~tationary-Upd~ting of the maximum ~s disabled while the car i~
stativnary. ~he main d~play show~ the current water temperature to ~he nearest degree cent;lgrade.

O~l ~emp~rat~L~
The top di~pl~Y 204 show~ to th~ nearest ~ lnteger the maXimum oll temperaeure in degreeY
centlgrade ~o ~ar encountered. When th~ car ~top~
and restar~s the maxlmum 1~ updated to the current reading after one mlnute~ as ln the ca~;e of the water tempera~urel to allow for the rise i~) oil temperature whilst the ~ar wa6 stationary~ ~pda~lng of the maximum i8 di~abled while the cAr i ~tationary. The ~ain display 203 shows the current oil tempe~ture to t~e neare8t degree centigrade.

Q~ 3~Ui~
The top di~play 20~ show~ to the nearest intege~ the mlnimum o~l prexsu~e :in PSI so far recorded wlth the engine rPnnln9 at n~ore than ~000 RPM slnce the ~y~tem was ~witched on. Thl~ dl~pl~y 35 is xctive continuou~ly. The maln dlsplay 203 ~hows the current oi 1 pre~sure in P~I to the neares~

intege~ .

The top di~pl~y 204 shows to the neares~
integer the minimum ~uel pressure in PSI -~o far re~orded w~th the engine runn$ng at ~ore than 750 ~PM
since the system was switched on. ~'hl~ d~splay 18 ~ctlve rontinuo~ly. The m~in dl~p]~y ~03 ~how~ the current fuel pres~re in PSI to the neare~t integ~r.

9~a~s~
Th~ top d~splay 204 ~how~ to the neare~t intege~ ~he minimum booRt pre~ure i.n PSI tl~s ~en so far recorded with the engine ~unning at more than 8000 RPM since the system was 6witched on. Thi~
display ls not active whilst the car is stationary.
~he main display 203 sho~ the curren~ boost pre~sure to the ne~rest tenth of a PSI.

Thls switch pos$tlon has two option~. The first option relayR information on the car's ~peed, the secc~nd optlon clear~ the top and main display 203s leaving the driver with no d~straction~ The driver can switch between the two option~ by pre~fiing the push-button switch 20~.

Tbe le~thand ~l~play 202 sho~s ~he ~ext ~6P~E~, t~e top displ~y 204 Ehow6 the a~te~t ~peed attained on the pre~ious lap and the maln d~play 203 shows loca~ speed maxima and minima to the nesrest tenth of a MPH. Display~ ng the most recent maxi~
and m$nimum speeds r~ives the dr$~er a ~ea~ure o~ how well he has taken ~ ~orner. As 800n a~ the car'~
~peed ~egin~ to increa~e after thc 810we8t p~rt of a 35 corner the minim~lm speed reached i~ displayed.
~ub~es~uently , a~ ~oon as the oar '8 speed begin to de~ease after peaking on ~he followin~ straight, the maximu~ speed atta$ned i~ di~played~

In this ~ode the top and main di~play 203~ are blank while the lefthand di~play 20~ ~how~
~ppropriate text. ~hus the drlver ha~ no dlstr~c~ion~. .

Thl~ ~witch pos~tion allows the u~ec to lnspect the readin~s fro~ the dlsplay/proces or unit'~ analog input ch~nnels. ~he le~thand displaY 202 contaln~
text identifying the input, the m.ain display 203 ~how~ the reading and the top di~play 204 i~ blank.
The uBer 6wit~he~ between the rea,ding~ by presslng th~ pu~h-button switch 206. The ~arious readings a~e de~cribed ~elow. In this ~itch poSition RESET and MAS~R RESET are not enabled. The reading~ dlsplayed are ~ampled and updated ~ive time~ a second.

~he lefthand display 202 read~ ~VOLTS~ The maln di~play 203 ~ows the battery voltage to the neare~t ~enth of a volt.

The lefthand display 202 reads ~T~P~. The main dl~play 203 shows the ~y~te~'~ internal temperatu~e to the n~are~t degree centigrade.
'C~
~he lefthand display ~02 re~d~ ~YRO~. The m~in dlsplay 203 ~hows the in~ernal 'gyro' (u~ed for a~tom~t~cally ob~Aln a ~ap of tbe ~r~ek for the lap report) ~e~ding on a ~c~le of 0 to 1023.

I~CU- ~4~ c~
The lefthand dl~lay read~ ~Fq'-~a. The maln display 203 ~how~ the front right r~de height on a scale of 0-1023.

L4 13~1056 E~~h~
The lefthand di~l~y reads ~FT-2P. Th~ maln display 203 show& the front left ride height on a ~cale of 0-1023~

The lefthand disl~y reads ~Rr-~. The main display 203 sho~ the re~r rlght ride height on a ~ale of 0-1023.

The lefthand dislay read~ ~Rr-2~. The ma$n display 203 show~ the rear left r~de heigh~ on a scale of 0-1023 1~
~"
The system continually ~onitor~ the four core readin$~ and the battery level. A warning is l~sued to t.he drlver should any of the follow~ng conditionR 0 oc~U~:
1) Oil p~essure too low.
2) Water temperatUre too hi~h.
3) Oil temperature too high.

4) Boost or ~uel pres~ure t~o low.
~5 5) Battery l~v~l too low, When one o the~e conditions 1~ dete~ted the display î~ in~tan~ly cleared and the pro~lelD read~ng 18 then automatlc~lly shown to the ~river 80 that he 3~ can monitor it~ pro~res~. The le~th~nd d~ play 202 cont~ins tex~ ldentifylng the cr~tlcal reading.
Hence this w~ ay either ~A~ER~, ~O~L-T~, ~OIL-PR, L~ OOST~ 0~ ~VO~TS". The ~aln display 203 ~hows the reading. The reading i~ constantly updated until the driver a~knowledges the fault by pressing th~ pu~h-button sw~t~h 206. The ~y~tem then ralRe~
or lowe~ the appropriate thre~hhol~ v21ue 80 tha~ a further warning will not be i~ued untll A further deterioration of the condition ha~ taken place.
The p~evlous display i~ then restored. Should two or more warnln~ condl~ion~ occur ~imul~aneou~ly, the~

5 are proce~sed accordlng to th~ order of precedence ~hown above. When one warn~ng i~ ~cknowledged the nex~ i~ dlsplayed~
The thre~hhold ~alueg i n compa~150n wilth which these warning re l~ued can be set us~ ng swltch 10 position five.

Thls switch po6itlon allows the u~er to change thre~hhold values a~ooiated with the sy~tem 15 ~rnings. The thre~hhold values th;3t may be altered are maxim~ ~ater temperature, max~m~m oil temperature, mlni~um oil pres~ure 3nd ~ini~um boo~t pres8ure~ A MASTEPc RES~T t~ansfers c01-t~0l to a host peraonal ~omputer which i~ connected vla the cable plugg~d into ~he car's pr~nter po~t 113. Th~ host computer i8 then used to alter the 1:hreshhold values as de~ired. A R~SET allow~ the ~er to dl~pen~e wish any change~ to these va~ues that h~lve been made and rev~r~ to the original ~alue~.

Thi~ ~witah po~ltlon ifi used when cal~bration or recalibra~ion of sensors i~ required, for example, after replace~ent o a ~o~n or damaged ~ensor~

Thi~ switch p~sition si~ply allow~ ~he main display 203 to show ~he actual instan~aneou~ ~peed of the ~ar over the ~oad surface, thu~ functioning a~ an additional or al~ern~tive ~peedometer.

~ he purpose of the lap report is to provide the race engineer with immediately available information on ~he way ~n whlch englneerlng ~h~nge~ made to the car have afected the ~ar '8 performa,nce. The ~ys~em san produ~e 6~ x different types of lap report according to the needs of the englneer. The sy tem reference~ change~ in the cAr's petforman~e to previou5 fa~t lap of the ~lrcuit, known as the dat~m lap, u~inq an internal map of the circuit whiçh it automatically obtalns on the fi~t out~ng at ~ new venue. In order to urnish the 6y~tem with an internal image of the clrcuit the initialisatlon procedure de~cribed below must be cacried out. The report produced ls alway~ of the fastest lap of the mo~t recently ~ompleted outin~. an 'outin~' being an uninterrupted ~equen~e of laps, Flgure 4 i8 a flow diagram of the s~eps involved.
On arr~val at a new race track the firs~ task to be accompll~hed ~R to ~et ~he two para~eter~
ne¢e~sary ~or th~ lap reporter to funct~on - the wheel circ~mference and the number of cornera on the cir~u$t~ The6e are ~et u81ng 8wltch pos1tion eight.
The user perfor~s a MASTER RESE~ and then ~elect~ the appropriat~ value for each paramete~ by presaing the push-button switch 20~ a~ the dl~play ~ycles through the pOB~ible values of each parameter. Thi~ ~R
descrlbed in more detail below. The drlver t~en 3~ drive~ the ~ar round the track, almlng ~o a~h$eve a fast la~ on the raclng line with no extraneou~ turn~
or swerves (e.g cvert2klng manoeuvres). This lap i8 known as the mapping lap and enables the computer to form it~ internal lmage of the circ~it. When be ha~
driven a ~ le l~p he should ~tralghtaw~y press the p~sh-button before br~nging the car to a ~alt~
Pre~sing the button while the car i~ in motion 17 131 ~056 ~elects the most recent, completed lap as the mapping lap. Pre~sing tbe button after the car has stopped ~elect~ the fa~te~t lap ho far as the mapping 1AP.
AS 800n a~ the mapping lap ha~ been ~t ~nd the car 5 has re~urned to the plt l~ne, the r~ce englnee~ plugs the printer 110 or prlnter buffer/dl~p:Lay 110' in to the prlnter port 11~ and obt~inR ~he ~apping dat~
sheet descrlbed below.

Of the 8ix available type~ of lalp report, two, lncluding the standard l~p report, present the data rela~lve to a prev~ou~ lap kno~n a~ the datum lap.
The ~ystem automatlc~lly selec~s the fastest pr~vlous 15 lap a~ the d~tum lap, updating $~ every time the ~river drive~ a ~aster lap. However, tbere are ~ituatlons in which thls is not approp~ate, for example lf lt has been ralning, and 80 th~ facility exists to either prevent a new faete~t lap from becomlng the da~u~ lap o~ to force a le~ fa~t lap to be~o~e the new dat~lm lap. Thi~ involve~ using ~witch po~ltion eight and p~e8~ing the pu3h-button 8witch 206 in response to the p~ompts ~ and ~PORCÆ7"

respectlYely. Thi~ i8 descrlbed in mor~ detail below.

To ~e~ the lap report param~ters the u~er swtche~ to ~witch position eight and pe~orms a 30 M~STER RESE~. The sy~tem re~pond~ with the me~sage ~SEr ~P R~POR~, the text RS~T ~P~ appearln~ in the top di~play 204 and the t~xt RREPORT" appearing in the lefthand display 20~. The user r~3ponds by pre~in~ the push but~on ~w~ tch 206. ~he mes~a~e ~FI% ~ENDS~ then appears, the text ~FIX~ in the lefthand window, the text ~B~MD ~ in the top window.
~n the main display 203 a ~ounting se~uence i~

started, beginning at three and golng up to twenty-five. Each number remain~ on the di~play for one ~econd. The ~se~ pres6es the push-button ~wltch 206 when the numbe~ co~re~ponding to the num~er Of ~orner~ on the clr~lt appear~. :tf no number ~elected by the u~er the count~ng ~equence re~arts from three a~a~n~ When the u~er h~ selec~ed the numbcr of benas the me~age ~PIX ~ EL~ appears, the text ~IX~ ln the lefthand di~play 2fl2 and the ~ext 1~ ~WR~L~ in the top di8play 204. Again a counting sequence ~ppears in the maln di~play 203. The u~er pre~æe~ the pu~h-button switch 206 when the approprlate wheel cir~umferen~e measurement appears on the screen. The ~creen then flashe~ several times be~ore displaying the messa~e ~SE~ ~AP~, the text ~SETU in the lefthand display ~02, the text "MAP~ ln the top di~play 2~4. The driver then atte~pts to d~ive a suitable mapping lap. When he iQ ~ati~fied that he ha~ drlven a ~uitable lap he can m~ke 1~
~0 become the mapping lap by pressint3 the pu~h-button swltch 206. ~f the 6wltch i~ pressed while the ~a~
i~ stlll in motion the ~08t re~ently completed lap becomes the mapping lap. If the car ha~ come to a halt befo~e the drlver pre~eR the ~witch, pre~ ~ng ~he ~wltch select~ the fastest lap driven ~ln~e the MASTER ~E8ET as the m~pping lap.
The datum lap i normally the faste~t lap dr~ven ~o far. If on his mo8t recent outing the drlver drive~ a fa6ter l~p, the lap repor~ produced will be relative to the old datum lap but the ne~/
fa~ter l~p wlll automatically ~ecome the new datum lap. ~he engineer can use ~wltch poRition elght to ove~r1de thi~ proce~s.
~ f the faste~t lap on the ~o$t recent outing wa~ fa~ter than the datum lap, turning to ~witch poS~tion eight yield~ the following; ~he lefthand di~play 202 ~hows N~AP nn- ~he~ nn is the lap n~mber of the la~t lap, the main di~play 203 contaln~
the lap time of the new faste~t lap and the top di~play 204 show~ the text ~BTO~. Pre~in~ the push-button ~wltch 206 prevent~ the new f~te~t lap S from becoming the datum lap, and the mess~ge ~VE~O~D~
appear~ ln the top di8play 20~.
Altern~tivelyO ~ the fa~te~t lap on the most recently co~pleted outing was ~lower ~han the pre~ent datum 12p, turnlng to swltch po&it~on eight ylelds 1~ the followlng: the lefthand d~play 202 ~hows the lap number a~ above, the maln di~play 2~3 ~ho~g the lap time of the faste~t lap of the mo~t recently completed outing, snd the top d~,play 204 contalns the text ~PO~B~. Pre~fiing the p~h-button swit~h 206 makes this lap, the ~aste~t of the mo~t recent outlng, the ne~ d~t~m lap. The me~age ~FORcED~
appear~ in the top di~play 204.
A RESET in thls ~witch position changes the scre~n, ~howlng the text ~DAT~, in the top dl~play 204, the lap number of the lap on whlch the c~rrent datum lap ~lme ~as set in th~ lefthand display 20 and the dat~m lap t~me in the main dlsplay 203. Thi8 ~reen di8play la~tB for five ~econd~, then th~
previooG i~formatlon reappea~6. Thl,s la~t d~s~lay ormat i~ also what one wlll see in ~wit~h po~ition elght after the ou~lng on which the mapping lap has been set, 81nce there are no prev~ous outings ~or compari~on ~
~ hen the ~r ~omeg to a halt ~fter ~he outing on which the mapp~ng lap ha~ ~een ~et the engineer can obtain a printou~ ~howing the way in which the ~ystem has cho~en to divide the track into ~egment~.
3S A segment con i~ts of elther a corner or the ~ra~ht between tw~ corn~r~. For each segment the ~ollowing information 1B gi~en: the length of the segmen~ in metre~, the time ta~en for the car to ~over the ~egment, the maxi~l~m or min~mum speed for st~aiqhts and ~orner~ re~pectlvely, and ~he segment type.
Segment~ are ela~f$ed A~ either ~traight~, f~st S corner~, medium corners or slow corners. ~he en~ineer may then uae thls lnformatlon to supplement that shown on the pre-printed sheet.0 To obtaln thi~
print~ut the ~ser loads tbe printer wlth a plain plece of A5 paper and plug8 th~ p~rinter cable ~nto the car'~ printer port 113 ot the buff~r/display unlt 110'. Print~ng proceeds automatlcally~

The ~tandard lap repo~t ~see Fig. 2) is printed on a pre-p~$nted sheet 300. Thi~ ~heet ~ho~
a m~p 301 of the circ~it with the corner6 numbered and has ~ection~ i~ whlch the 6y~tem prin~s speed changes 30~ and a lap summary 303. The total lap elm~ ~nd the straight-line speed are shown and compared ~lth tho8e of the datum laEI. There ~8 al~o ~ ~pace ~et ~side ~o~ the engineerR handwritten comments.
In the speed change ~ectlon the Ry~tem lîst~ in order of magnitude the flve mo~t signlficant speed change~ on the lap rela~ive to the datum lap. The~e ~y be on ~traigh~ segmentQ, corner ~egment~ or on entry or exlt to corner segment~ Corner entry and exit tlmes are denoted by the suffixes IN and O~T
respectively.
In the lap ~ummary section the number of ~peed g~ins on entry and exit to ~orners of each type ifi printed.

Obtaining the ~tandard l~p report i~ a straightforward proees~ pro~iding the mappin~ lap ha~
been ~et. The printer i~ loaded wlth a pre-printed 21 1 31~Or3~

lap report ~heet. As the car cvme~ to a halt ln the plt lane ~ter an outlng, the u~e~ ~lmply plug~ the printer cable into the car'~ printer po~t 113.
Al~ernatlvely~ ~he prlnter bufferJdi~play 1~0' i8 S plugged ln to the port 113 and data tran~erred to it, the printer later belng pluuged ln~o the untt 110'. Print~ng then takes place automatically.

The ~y~tem print~ out ~or display~ on tbe printer bu~fe~di~play~ a report oll the faste~t lap of the ~o~t recent outlng in the form ~elected hy the user. The engineer can sele~t the de~ieed form using sw~ tch po~ition nine. To obtaln the ~tandard lap report lt ~8 not necessary to sw~tch to posltlon nine. However, if for example a second copy of it i8 req~ired, lt can be obtalned u~inSI switch po~itlon nine. Only the stand~rd lap report (oEIt~ on one) u~es the pre-printed sheet. ~or all other type~ o~ lap 20 repo~t the prl nter mu~t fir~t be loaded with a plaln ~heet of A5 paper be~ore tbe printer cable i~ plugged into the prlnte~ port 113. The cholces of lap report are are as follow~;

1) ~ R"
Report 8howing time~ and speed~ of fa8te~t lap of last outing relatl~e to the datum lap ~ ~The ~tandard lap report ~ .

2) UL~P-A"
Report ~howing actual tlme~ and speeds of fa~te~t lap of last outing.

3) ~Spd-~
Graph showiny ~pe~d versus distance for fa~te~t lap o~ la~t outing ~el~tive to the datum lap.

13~ ~56 4~ ~pd-A~
Graph ~howing actual ~peed versu~ dl~ance for fa~te t lap of 1ast out:ln~

5) URP~
~aph ~howing ~P~ vers~ls di~tance on fasteæ~ lap of las~ outin9.

~;) DBO~T"
~raph of boost pres~ure versu~ distance on fastest lap of last outing ~if deslred).

In 6witch pos~tion n~ne the left hand display cyc1es through the available ~holces (LAP-~, LAP-A
etc. as 1 iRted above ) displaying ea~h for one ~econd~ To aelect the desired format the ~ser presses the push-button ~witch 20~ while the required ~ option i~ 8howing. The maln di8play 203 then f1ashe~
until the printer is plugged ln or the nine-posltion ~wltch 205 se~tlng i~ changed. when pr~nting ls completed the 1eft hand dlsp1ay agaln cycle~ through the a~allable choi~e~.

The push-button 20~ switch located on the top left hand ~lde i~ used in a number of ~if~erent way8:
-~ O
~L~s~.
In the maiority of ca~e~ th~ button 1~ ju~t pres~ed down momentari~y in order to make a selectîon or to page through the diffe~ent optlon~ avail~bl~ on ea~h setting of the nine-po~ltion ~wit~h 205. The ~oment the b~tton 1~ p~6hed down, ~he 1Ower left dl~play changes from whate~er text it i~ pre~ently showlng to just A :llne; ' ~ ' . Thls glves the oper~tor feed~ck that the pre~s has worked ok. If the button i~ relea~ed within 1.5 ~econds the 5 co~pute~ interp~et~ the pres~ a~ a mo~ent~ry pre~

~h~E~
Sometime~ lt 1~ nece~ary to reset ~ ce~taln funct ~ on, for ln~tan~e when the ~ystem 18 ~oun~ing 10 lap~ ~qnd it i~ requlred to re~et the counter back to zero. Thi~ i~ achieved $i~ply by holdlng tbe but~on down for a~ long as it take6 the word ~RESETI to appear in ~he left hand text wlndow.
In order for the ~y~tem to tell the diffe~ence 15 between a momentary pre~ and a long 're~et ' press the ~oftware con~tantly monltors the switch. If it detect~ a transition f rom ~wit~h up to ~witch down it flr~t clear~ the left displ~y and then se~s a timer in motion, a tran~i~ion rom down to up halts the tl~er. I~ the tim~r reads les~ than 1.5 ~econd~ the ~y~te~ interpret~ the pre~s a~ a mo~entary one. If greater th~n 1.5 ~econd8 ~ '~e~et' pre~R i~ assumed and 'RESET' 1~ sent to the display. A li~tle practi6e makes tbe dlfference cle~r~ ThiR form of switch pre~q is only approp~ate to ~ome o~ the av~ilable optlon~.

~c~ ~ 'MA~T~ RES~' The~e i~ one ~ddlt~on~l type of p~es~ r only used when very dellberate actlon is required, for ln~tanc~ when ~t 1~ needed to tell the syste~ tha~
the ~ext run 1~ at a new ~i~cuit. This i~ called a ma~ter reset ~nd ls only appropr:i~te to a few ~ettings. Here one hol~6 the ~utton down for a full ~0 second ~e~ore releasing. The dl~play will ~how 'RES~T' in the left hand display, and after about 5 second~ the m~ln dl~play 2~3 w$11 start to count down to zero a~ one se~ond intervals. If the butto~ i~

released ~t any time while the count down i~ ~howing lt is ~5 though the button had never been pressed at all. ~Thu~ gl~ing ~ way out if ~ne change~ one's mind About ~ivlng the mac~ine a normal reset.) If one pe~ t~ the count will eventually reach zero, the di~play will fla~h '~ASTER' andi then '~ESET', and a ma~ter reset will have been achie~ved. As with normal 'RE~ET' the master re~et ix only appropriate ~o ce~tain options.

~S

Claims (11)

1. A vehicle data recording system for connection to one or more analog sensors, and for storing data from the sensor(s) in a memory during a plurality of chosen periods, the system comprising:
analog/digital conversion means for converting analog data from the sensor(s) into digital data;
means for triggering a procedure for storing of the data into memory;
means for automatically starting and ending periods of storing of the data in memory;
means for storing in memory a set of data for a datum period;
means for storing further sets of data in a memory;
means for comparing a set of data stored during a first period with a set of data stored during a further period and selecting for retention in memory one of the sets of data in accordance with a predetermined algorithm; and, means for comparing said retained set of data with the datum set and outputting differences between said datum set and said selected set.

2. A system according to claim 1, wherein the means for automatically starting and ending periods of storing of the data in memory comprises;
a transmitter for transmitting a beacon signal;
a receiver for monitoring for the presence of the beacon signal; and, means responsive to the receipt of the beacon signal to indicate the end of one set of data and the start of a further set.

3. A system according to claim 1, wherein the means for triggering a procedure for storing of the data into memory includes a manually operable switch actuable by the driver of a vehicle in which the system is installed.

4. A system according to claim 2, wherein the means for triggering a procedure for storing of the data into memory includes a manually operable switch actuable by the driver of a vehicle in which the system is installed.

5. A system according to claim 1, wherein the means for displaying the differences between the datum set and the selected set includes a printer removably attachable to the system.

6. A system according claim 2, wherein the means for displaying the differences between the datum set and the selected set includes a printer removably attachable to the system.

7. A system according to claim 3, wherein the means for displaying the differences between the datum set and the selected set includes a printer removably attachable to the system.

8. A system according to claim 4, wherein the means for displaying the differences between the datum set and the selected set includes a printer removably attachable to the system.

9. A system according to claims 1, 2 or 3, wherein the means for displaying the differences between the datum set and the selected set includes a data buffer/display unit which includes a RAM in which data can be stored temporarily and then displayed/previewed on an integral liquid crystal display and/or outputted to a printer, or computer.

10. A system according to claims 4, 5 or 6, wherein the means for displaying the differences between the datum set and the selected set includes a data buffer/display unit which includes a RAM in which data can be stored temporarily and then displayed/previewed on an integral liquid crystal display and/or outputted to a printer, or computer.

11. A system according to claims 7 or 8, wherein the means for displaying the differences between the datum set and the selected set includes a data buffer/display unit which includes a RAM in which data can be stored temporarily and then displayed/previewed on an integral liquid crystal display and/or outputted to a printer, or computer.