Synopsys, Inc. · NASDAQ:SNPS
Synopsys — Technical Presentation (October 2002)
21 slides from Synopsys's technical presentation, Oct 8, 2002
Slide 1: A virtual prototyping for the Netlander Martian probes EPS
A virtual prototyping for the Netlander Martian probes EPS Stéphane FREDON CNES Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 1
Slide 2: Mission objectives
Mission objectives • Priority on network science – synchronised measurements by several (4) landers – main scientific areas : internal structure, meteorology • Additional scientific objectives – multi-site experiments – main scientific areas : subsurface structure, surface mineralogy, local geology
Slide 3: NetLander Probe
NetLander Probe Electric Panoramic field Camera Microphone Meteo boom Ground Penetrating Radar Radioscience Seismometer Magnetometer Soil Properties Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 3
Slide 4: Simulation tool presentation: global modelisation need
Simulation tool presentation Global modelisation need Position : Solar longitude Latitude Longitude Crossing of the atmosphere : A IGS = fct(Ecl) direct and diffuse radiation Ibat Battery regulator Power Solar consumption array Battery Effects of the shadows Vbat B Technological choices : electrical
Slide 5: Simulation tool presentation: central role of SABER
Simulation tool presentation Central role of SABER ® Power consumption Atmosphere model data (ASCII) (FORTRAN) SABER® Shadow casting Electrical model (FORTRAN) (MAST) Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 5
Slide 6: Presentation of OPEN GUI
Simulation tool presentation Presentation of OPEN GUI Friendly graphic user interface Every parameters easily accessible with several dedicated pages: Simulation page Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 6
Slide 7: Presentation of OPEN GUI: geometry and architecture pages
Simulation tool presentation Presentation of OPEN GUI Geometry page Architecture page Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 7
Slide 8: Specific model: solar flux on Mars
Simulation tool presentation Specific model : solar flux on Mars Solar flux on Mars divided in scattered and direct fluxes function of : – season (date) – latitude – time – the weather conditions : optical depth between τ=0.3 (clear sky) and τ=5 (dust storm) Tuesday 8th October 2002 - SNUG Saber - M
Slide 9: Specific model: shadow casting
OPEN simulation tool presentation Specifid model : shadow casting Shadow effect depends on : • The geometry of the surface module : – elements external appendices of the module (antenna, …) • The Martian environment : – landing site • The position of the sun Model developed in Fortran Geometry of a
Slide 10: Partial shading of a solar array
OPEN simulation tool presentation Partial shading of a solar array Diffuse flux Direct flux current current voltage voltage Cell in the shade Cell in the sun Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 10
Slide 11: Partial shading of a solar array: protection diode
OPEN simulation tool presentation Partial shading of a solar array Protection diode for each cell Consequent loss of power for the whole array Characteristics of the single cells Characteristic of the in the string global string Lightened cell Shaded cell Tuesday 8th October 2002 - SNUG Saber - Muni
Slide 12: The electrical power subsystem
Application : Mission duration estimates The electrical power subsystem IG S = fc t(E c l) Ib at B a tte ry r e g u la to r P ow er S o la r c o n s u m p tio n a rra y B a tte ry V bat • Unregulated bus : – [13.5V, 20.5 V] • Solar arrays : – five solar panels populed with 4 strings of 40 silicon ce
Slide 13: Power hypothesis
Application : Mission duration estimates Power hypothesis • Network mission consumption : 5.7 W all the time • Telecom session consumption : 2W during 5min by night (RX) 20 W during 4 min by night (RX & TX) • Neige session consumption : 40W during 20 min by night • Heater session consumption : 0.3W
Slide 14: General hypothesis
Application : Mission duration estimates General hypothesis • Netlander landing date : 121° solar longitude • Power loss rate with dust accumulation : 0.18% per sol (Dave CRIPS, NASA, hypothesis) • No radiation degradation on Solar Array • Effective cell capacity: 3.5Ah Cell model resulting from a m
Slide 15: Simulation results
Application : Mission duration estimates Simulation results Capacity battery Bus voltage Battery current Power consumption Solar flux Temperature of the solar arrays Solar arrays voltage Currents of the solar arrays Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 15
Slide 16: Simulation results: nominal mission not fully ensured
Application : Mission duration estimates Simulation results Nominal mission not fully ensured Latitude for a given latitude 30°N 450 0° 240 Sol 100 200 300 400 500 600 30°S Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 16
Slide 17: Simulation results
Application : Mission duration estimates Simulation results Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 17
Slide 18: Study of sensibility
Application : Mission duration estimates Study of sensibility Study of sensitivity on parameters : – dust accumulation criteria – power consumption Tuesday 8th October 2002 - SNUG Saber - Munich S. FREDON 18
Slide 19: Sensibility: dust accumulation criteria
Application : Mission duration estimates Study of sensibility Result with a criteria of 0.12% solar array power loss per sol : Latitude Nominal mission not ensured for a latitude given 30°N 480 Sol 0° 100 200 300 400 500 600 30°S => A criteria of 0.015% per sol is necessary for one year mission dura
Slide 20: Sensibility: network mission consumption
Application : Mission duration estimates Study of sensibility Result with a network mission consumption of 5W : Latitude Nominal mission not ensured for a latitude given 30°N 480 Sol 0° 100 200 300 400 500 600 30°S => A network mission consumption of 2W is necessary for one year mission duration Tue
Slide 21: Conclusion
Conclusion • Operational virtual prototype which simulates the EPS behavior working in its final environment, on Mars. • Significant impacts on the design : – number of solar arrays : 3 in phase A, 5 in B phase – optimization of the choice of an electrical architecture • Assistance to reduce major r