Computer Graphics Applications to Crew Displays

Transcription

1 Fairfield Universiy Mahemaics Faculy Publicaions Mahemaics Deparmen Compuer Graphics Applicaions o Crew Displays Joan Wyzkoski Weiss Fairfield Universiy, weiss@fairfield.edu The definiive version of his aricle is available on NASA repor server a: hp://nrs.nasa.gov/archive/nasa/casi.nrs.nasa.gov/ _ pdf Reposiory Ciaion Weiss, Joan Wyzkoski, "Compuer Graphics Applicaions o Crew Displays" (1983). Mahemaics Faculy Publicaions. 46. hp://digialcommons.fairfield.edu/mahandcompuerscience-faculypubs/46 Published Ciaion Wyzkoski [Weiss], Joan (1983). Compuer Graphics Applicaions o Crew Displays, NASA Research Repor, Augus This Aricle is brough o you for free and open access by he Mahemaics Deparmen a DigialCommons@Fairfield. has been acceped for inclusion in Mahemaics Faculy Publicaions by an auhorized adminisraor of DigialCommons@Fairfield. For more informaion, please conac digialcommons@fairfield.edu.

2 ',K. _,, -, _: COMPUTER GRAPH CS APF'L CAT ONS _ TO CREW DSPLAYS N , Joan Wyz koski Assisan Professor ' Deparmer. of Mahemaics L Bradley Universiy Peori _, llinois 61625, _ ABSTRACT c - j - Asronaus are provided much daa and intormaion via he monchrome CRT displays on he orbier. For his projec wo _- _ areas were invesigaed for he possible inroducion of compuer graphics o enhance and exend he uiliy of hese displays. : One involved r_viewing he curren orbier displays and idenifying hose which could be improved via compuer graphics. A_ an example, he abular daa on elecrical power disribuion and conrol was enhanced by he addiion of color and bar chars. The oher deal wih he developmen of an aid o berhing a payload wih he Remoe Manipulaor Sysem (RMS). This aid consiss of a graphics display of he op, fron and side views of he payload and cargo bay and poin of resoluion (POR) posiion and aiude daa for he curren locaion of he payload. The iniial implemenaion was on an BM PC clone. This program previews he demonsraion sofware insalled in he Johnson Space bener Manipulaor Developmen Faciliy (MDF). Due o curren hardware limiaions, he MDF version is slow, i.e. ",, abou a 4c_+ second updae rae and, hence, no "real-ime. " Despie hi_ fac, he evaluaion of his addiional visual cue as an RMS operaor aid indic'aes ha his display, wih modificaions for _peed, ec., can assis he crew. Furher developmen is appropriae. ( k i 27-1

3 ',_. _o.f _ ;_. _ "., i NTRODUCT ON _" Color and graphics, if carefully seleced, enhan_.e he display and undersanding of daa. Compuer graphics, in paricular color graphics, furnishes an excellen means o improve he presenaion of informaion. This, in urn, " T encourages quicker inerpreaion and, hence, response o daa. More efficien response o informaion faciliaes man-machine ineracion.! Orbier compuer CRT displays provide much daa and ' _j informaion o he crew. Reviewing hese displays and _ idenifying hose which can be enhanced via compuer graphics was one face of he projec. The oher area of invesigaion - involved he developmen of an aid o faciliae payload berhing by he Remoe Manipulaor Sysem (RMS) operaor. Displays Numerous CRT displays are selecable by he crew during each fligh of he shule. These -how daa and informaion in a 4 variey of formas. Some are quie specific and apply o he ascen and reenry of he orbier. Ohers indicae he saus of _ ; he various shule sysems and ypically are in abular form. All he di_piays were reviewed. A display of he daa on elecrical power disribuion and conrol was chosen o demonsrae a possible enhancemen of displays. Color and bar i chars replace abular digial daa. Mos enries have a high(h), medium(m) or low(l) range. Red, green and yellow, _i respecively indicae each range, n order o respond o he -,., 27-2 l_,..

4 ; high range of a paricular porion of he elecrical sysem, \ spoing a "red" condiion is easier han spoing an "H". Payload Berhing Aid To berh a payload _he RMS operaor, working in he af 4fligh deck, currenly uses several visual cues. n mos cases a porion of he payload can be viewed from he wo af payload bay _-_ viewing windows. Sarboard and por TV cameras are posiioned on e he fore and af bulkheads of he cargo b_y. Two of,ers are _:_. locaed a he elbow and wris, respecively, of he manipulaor -<-! a arm. On moniors, locaed in he af fligh deck, he operaor can selec views from Lip o four of he cameras. Digial o _ informaion abou he posiion and aiude of he poin of =! : resoluiod (POR) of he payload (This is explained in he Theory ', secion.) is also available. An addiional visuel cue o aid in payload berhing was i! : developed. This aid consiss of a compuer graphics display of he op, fron and side views of he payload ano car oo bay along wih he POR posiion and aiude daa. See figures 1 and 2.. THEORY T_,e choice of colors and he selecion of an appropriae -_ 27-3 i_ graphic enhanceddi_pl=_y p'ayed for he maj r 0rbi_r. r' les in he implemenai n f an i_.:

5 .+,! : Developing he sofware o display he updaed views of he payload required some mahemaical analysis and compuaion. As shown in figure 3_ he orbier coordinae sysem is a "*, righ-handed sysem. The posiive _:-a,,:isis forward, he y-a,,:is is sarboard and z is down. The POR is a preseleced poin wihin he payload. The posiion is indicaed as x, yj z values in he orbier coordinae sysem. The aiude of he payload, or he pich, yaw and roll of he payload which would orien i - ino is presen aiude., is a series of roaions abou lines " p i ;2_ passing hrough he specified coi_rol poin and parallel o he appropriae orbier axis. Pich is a roaion abou he orbier y-a,,:is in a clockwise direcion. A counerclockwise roaion + abou he orbier's z-a,'is produces yaw. While a clockwise roaion abou he >:-a:.:i_of he orbier causes he payload o roll. Three dimensional daa bases along wih h_ appropriae _ l move/draw specificaions were defined for he cargo bay and _.! payload, respecively. These daa poins are placed in n(# of daa poins for he cargo bay or payload) by 3 marices. The updaed posiion of he payload is a ranslaion by he change in,x, y and z, respecively. The_e changes are added o he ) respecive coordinaes o-_" each daa poin for he payload. The roaions o accomplish pich, yaw and roll are easily represened as 3 by 3 marices (See Foley and Van Dam_ 1982, pp B. Noe, 4 by 4 marices are no necessary for his applicaion.). Composiion of hese marices and hen a marix mul_pl_... ion of he daa e wih he POR cenered a he ff,,,w_...++ _..

6 origin of he orbier coordinae sysem, creae ne_, ransformed daa poins of he payload. [" To show he op vi w, he _:,y values, ransformed o screen coordinaes, are ploed. The fron view is a plo of he y,z values and he x,z values are drawn for he side v._ew. T " 9 MPLEMENTATON p _[ The sample orbier display, he curren and enhanced _ versions, and he RMS berhing aid were implemene _ in color on i an BM PC clone. These programs are basically for :_ den,onsraions, alhough much poenial exiss for applicaion L i of compuer graphics on he orbier. Using he POR daa fro,_. an _: acual berhing procedure, he berhing display updaed appro_:imaely every 12 seconds. See figures 1 and 2. n order o evaluae he effeciveness of his payload berhing aid, he displays were implemened on a ZSO } microprocessor equipped wih a Microangelo card and displayed on a monochrome graphics monior. This is inerfaced wih he SE1 i _ ( compuer which conrols and monior_ he Manipulaor Developmen Faciliy (MDF). [The MDF is a JSC raining faciliy for RMS operaors.] During a _ayload berhing maneuver, curren POR daa is sen o he Z80 microprocessor, which draws he appropriae,_ display for he operaor o view. Due o _he limiaions of he _ f h_,r'dware, especially ho 8 bi processor, i-he updae rae is 1 _,_u 40 seconds for a full display ",

7 ,,4 _ i 1 RESULTS The sample displays appear o have poenial bu have no been adequaely evaluaed. This is mainly due o he emphasis and ime devoed o he MDF berhing aid.,_ The response by he MDF/RMS operaors o he payload berhing aid has been very favorable. The presen sysem was developed wih he hardware which was on hand a asc and coss _" less han $4000. Viewed as an iniial sep in he developmen of a close o real-ime berhing aid, he curren sysem shows much _._._ poenial. The slow updae rae of he display, excep as a _ demonsraion, is no accepable. This is easily remedied by a ] beer, more powerful processor which is readily available. FUTURE ENHANCEMENTS AND DRECTONS An obvious direcion of he orbier display porion of he projec is addiion_l review of he displays in order o idenify,_ specific caegories of he displays and he corresponding color compuer graphics enhancemens. This review will also benefi curren definiion of space saion sysems display requiremens. The uiliy of he payload berhing aid has been demonsraed. is apparen ha speeding up he refresh rae of he display is he firs goal. Oher enhancemens could include graphical indicaions of he collision of he payloa_ wih he cargo hay and he abiliy o selec, via keysroke.._, -_i 27-6 i

8 ligh pen or some oher ineracive device, a porion of he display on which o zoom. Zooming in on a paricular segmen of : he display would allow he operaor o see he fine deail ha -. is helpful in he final sages of berhing. Furher developmen of his compuer graphics payload/cargo bay display will _cerainly indicae addiional refinemens and enhancemens. _EFERENCES 1. Angell, fan 0. F'RACTCAL NTRODUCTON TO COMPUTER '_ GRAPHCS, Halsed F'ress (,John Wiley), NY, 1981 m- f_ 2. Foley, James D. and Andries Van Dam, FUNDAMENTALS OF :_ NTERACTVE COMPUTER GRAPHCS, Addison-Wesley, Reading, MA, Rogers, David F. and 3. Alan Adams, MATHEMATCAL ELEMENTS FOR COMPUTER GRAPHCS, McGraw-Hill, NY, : i T 27-7 "

9 .../_.!.: - )_.2.._,. ".." 1 1.! -j.i i ) l, in il? Figure. BM PC demonsraionof a ypical payload b6rhingdisplay. Beginningin he upper lef-handcorner in a counerclockwise : direcion, he op, fron and side views of he payloadand cargo bay,and he poin of resoluion posiion and aiude daa are displayed._,? [ "4 x b 6(. i i ' '_' 27-8,

10 111 f k,4 F Figure 2. BFPC demonsraionof a berhed payloaddisplay. Beginning in he upper lef-handcorner and moving in a counerc)ockwisedirecion, he op, fron and side views of he payload and cargo bay,and he poin of _" resoluion posiion and aiudedaa are displayed., (!.... _.mmmh,dwa_..p. 27-9

11 ( -. ORG;4ALp;..G_.;-_ ; OF.pOORQUALTY,. / o 4W" Z li',, 0"1 O_lHl_n OOYAX! '_- \ J" k_ RO.L :" OPERATOR ROTATON REFERENCEAXES _: " OPERATOR Y TRANSLATON REFEREf;CE AXES k ;? - 'mr_ ORBTER BODYAXES X Z "i Fiq(_re 3. O_Lie_ Oody and F_,yic)d qefere_ce Axes 1._: % _.' '