After Break Session: Electronics: Jim, Deepak Communications, Power, Thermal, Sensors - laser Com Deepak Requirements: Control from remote site- non line of site Uninterupted - reliable 2Mbs used for Panos 500 Kbs to download code Range of up to 10 Kms between Rover and relay less movement of relay stations - more reliable Murph how hard to move relay antenna Com dish mounted on com truck Relay station 2 raios 2 fiber modems Logistics problem to move antenna - take more than a few hours to move Done in a day Current Config Robot - relay staion max 10 km - com truck with fiber links - 100 -200 meters from relay station. Com truck to satellite - down link in Miami, not a big enough dish in Pittsburgh 9 meter dish because of low power Red Is it option to purchase extra power to send signal to Pit There is one dish in Pit Cost of landline 5K per month Taken care of by satellite vendor Can have multiple land lines from Miami John Equipment on Com truck who does it belong to Mostly vendor Block Diagram Robot Wireless Ethernet and Radio Radio on all the time Relay Station option instead of fiber use another wireless Fiber max length 1 km Dave Fiber heavy as much trouble to run fiber as to move the relay antenna Most of the time be less than 200m distance between relay station and truck Dave Wind problem with fiber Wind defineatley a factor to shut down the operation Red Possibility of wind sensing on the weather station It does exist John Pointing capability at the relay station Flat plate antennas used for wireless ethernet at both ends need gps data to point antenna to rover because rover moving so slow allows tracking is there a motor to move the relay antenna added wieght need power source ther is a generator to go to the relay station Bares Can you park control truck on the top of the hill and not have the relay station Hills to steep to climb with a truck End up carrying relay antenna to the top Lalit If you shorten line of sight s distance to 2-5 km Need the coverage of the high peaks for line of sight Bares If terrain is flat why can't the truck be driven to the top of the hill Still not an option Dave full days work to move relay station Atacama video: Will visit all sites in the video 4. Elevation approx 2400 m first site fairly flat Rocks .5 meter river beds up to 2 meters deep How many relays 6-8 setups 7 days a week with setup over night (operation) Natural night illumination to allow setups and for pictures terrain loose on surface 3rd site 3000 m elevation 4th site sharp rocks transitions in elevations problem for line of site how likely to maintain line of site flat portion in the middle with the sides of the site containing the rough terrain. Small dunes on video up to 50 ft high Ridge hans Raise antenna height on rover another meter to get better los put crank up tower on relay station Oscilation of antenna digital links ok analog links could cause problems red concern of dynamics of vehicle antenna 1 kg pointing system can get heavy what is the payoff of pursuing a high res topographic map of the specific regions to be travelled ability to visualize route before the fact do reconaaissaince whe we are down there can take care of it Use a civil AE firm to produce a map along path 40 k lead time ? get a friendly firm to due the processing but need the imagery Mike B what is chance of interference of the radios from the mining companies applications are in for permits deepak voice interface between the control truck and pittsburgh control truck sat dish, modem, control station, 3.4 m dish mounted on dish enclosure for people inside the truck Murph truck has romm to add 4- terminals 4 wheels drive version of mid size U haul sat equipment does not take too much space sat dish on truck can take some jostling test sat uplink in the last week of March Bares no need to test known technology sat uplink quite reliable need to ober fiber modems plan to use three wave testing next few weeks Murph What is degredation of line of sightr signal 70 degree beam width antenna tested red had substantial dropoff of data at 10 degree pointing error at three degrees expect 2mbits 50 percent of max throughput hans pointing accuracy need 3-5 degrees at 10 degrees data drops off but don't lose the link murph antenna mounted pointing 3 degree pointing on rover accuracy 1.5 degree depending on gyrocompass at 15 degree roll/pitch 1 degree accuracy at 20Hz might need to use imu - hopefully not hans for antenna testing how did you set up initial alignement no specific method for initial alignment what is the impact of losing the signal as bouncing over rocks can take up to 3 sec to regain contact for com break - only panos affected command line- use modem Pointing requirements use of two slip rings 1 control tilt motor 1 azimuth - can have cable wrap some say slip rings no problem Bares it is 2 more connections so it is more unreliable what is loss of 5 ft of coax for a 360 turn why can't system unwind - happen once a day Novice drivers - drive in circles fuzzy requirement Murph how fast can you unwrap - under 1 sec will determine the affect Red Issue out on the table link rent for 1 month dave 200km traverse all happen with sat uplink no some before some after murph buy link by month or week must buy in 30 day chunks bares lease com truck in chile bolt dish on truck can you drive truck with dish on roof yes dish is collapsable what spec on the wind was give to sat vendor suppposedly ok with vendor next 2 weeks testing modems, control shell simulations, most sensors in house Issues non line of sight of the radio hope to go 2.5 miles without moving relay station low bandwidth backup scenario- repeaters mike b why not use low gain hans 3 db on vehicle 10 db on relay and get better distance bares wht is repeater scenario- they need power alex, use reflectors carry out and deploy repeaters - bandwidth goes down get solar powered repeaters three or 4 watts each repeater station 10k hans in event of loss of both low and high bandwidht need a recovery strategy go to last point that there was a link dave need to be able to got to a specific location red there will be a treverse from a to b dave this not baseline mark m map not useable ove long distance dave what system enable you to back up 2 m murph 10 meter map on navigation useable not safeguarded reverse hans vehicle smart enough to stop when certain pitch roll limits reached even without imaging, autonomy vehicle should be able to drive to a safe condition with a certain heading all on real time bares real time has to know that both radios are lost robot will stop and retrace path as soon as com lost Dave adding mor scope and capability than initialy designed hans simple things not on marsokhod for arizona testting like drive on a given heading to a safe posiition simple vs complicated strategies to mishap situaions bares tv truck towers that go up 40 ft put high gain antenna on that could truck always be in line of sight of vehicle within a mile of vehicle. alex no - with such a high antenna on vehicle can't drive on the offroad, bares possibilites to keep rover within 1 mile of road alex to keep lunar relevent need to keep area around rover clear. usually 3-4 miles away from road bares if everything could be on truck much simpler leap frog truck every few hours half hour alignment of dish too much equipment strung all over the place Jim Onboard Power pppppppppppp total 1,9 kw internal 120 vac so that off the shelf equipment useable gas driven alternator isolate computing equip - include a ups power system in 2 portions directly from alternator protected bus supporting computing, com, sensors real time sys manages power for each system sensors take dc sensors driven through their own power supply Bares how are circuit breakers actively controlled have breakers and solid state relays how to reset breakers once they trip mike b use thermal breakers that reset or magnetic breakers hans thermal breakers make sense bares what does breaker protect you from for safety hans arrange breakers so that a single breaker can't take out two wheels lalit cycle time of solid state relays can't take care of catastrophic failures sib breakers last safeguard bares take them out after initial setup another component what is the point of ssr's if amp has no error signal can control values that way possible overdesign mike b solid state relays alot of extra complexity more trouble than they are worth fuses more reliable than breakers magnetic breakers can be tripped by a large shock bares why amp not matched to the motor extra component dc power supply, amp then motor form pac sci get amp that plugs into 120 v all matched pac sci amps are 6 times bigger can't handle amps that big made that size for a reason sib they are over designed we just need single phase considering multiple power supplies to get proper current in single phase hans talk to elmo about diode power supplies to gether, rectifier failure along the way subsystems real time a set of ac/dc converters vicor flat pak which has dc/dc hans can you bypass ssr and use gate in for load settings you can turn that on and off use inhibit lines wanted to retain original power supply for the imaging system get rid of all ssr's in the system no mixed bag of solves bares put weather station on truck part of science package relevant to antartica misssion single phase vs three phase ????????????????????????? mike b why isoloate different power supplies problems with noise bares normal fuctionality .6 gallons per hour tank 5-7 gallons 800w for locomotion at top speed\ power draw at peak torque at 2amps per motor approx 30 degree climb at 800w what speed at steepest climb approx .1 m/s ??? unknown figure hans any failsafe brakes gear trains are backdriveable on steep hill vehicle will roll down if generator drops out BAD NEWS - sib Current 300lb robot can not back drive with power off bares efficiency question Thermal total 857 w to dissipate 26.7 degree rise without any forced cooling with cooling 5 degree rise ambient temp 20 C = 30 C still acceptable lalit we have thermal shutoffs why have cooling? bares cooling have fins/filters that need to be cleaned hans talk to newark might be able to get away without cleaning them actual condition unknown - dust termal resistance calc to set size of fins mount dc/dc converters on the walls Laser ranger sys accuity range finger - continuous unit considering regal - higher power short pulses 12 w peak worried that accuity have performance degradation due to dust reid what makes reigel better - heavier, bigger, slightly longer range, higher power gives better range reid so can filter out initial returns and get the strongest pulse hans only used for close prox performance could enclose the laser in a ported houseing then the accuity would be better tried viser but caused internal reflection want to try filtered air lalit lead time of new laser hans unaware of laser system in dusty environment for 30 days without a problem bares had problem with lead time already bare mirror may still be a reality trying to get reange of 3 m how about other spot sensors spatial resolution less than .25 of a meter hans why do you need a scanning system at all need it to find drop offs and high obstacles bares stop distance less than .5 m 1 sec to stop I can't hear hans now way sensor will survive for a month NO WAY LACK OF PRECEDENCE red no prospect for a long term program scanning sensor not in the research agenda community has not gone back to spot sensors, or other sensors bares go to another sensor reid spectral light consensus can't run spectral light outdoors red it is on its way to mars lalit why not go with sonar that works red lunar relevance hans move laser on linear scale - gets rid of rotating mirror do not need high scan rates reid need a couple hertz hans use three lasers murph NO LASER REAL TROUBLE SPOT