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GPS/INS Computing System. Performed by: Alexander Pavlov David Domb Supervisor: Mony Orbach. Project Characterization Spring 2008/9. Agenda. 1. General overview. 2. Our Project. 3. Working environment. 4. Design Solution. 5. Timeline. General overview.
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GPS/INS Computing System Performed by: Alexander Pavlov David Domb Supervisor: Mony Orbach Project Characterization Spring 2008/9
Agenda 1. General overview 2. Our Project 3. Working environment 4. Design Solution 5. Timeline GPS/INS Computing System
General overview “Even Noah got no salary for the first six months partly on account of the weather and partly because he was learning navigation.” Mark Twain GPS/INS Computing System
INS Characteristics Self-contained Provides accurate position and velocity over short time periods but slowly drifts over time More expensive and heavier than GPS GPS Characteristics Relies on GPS satellites: susceptible to jamming, RF interference, multipath and integrity problems Provides accurate position and velocity over longer time periods but has high frequency noise GPS/INS navigation Both Global Positioning System (GPS) and Inertial Navigation System (INS) has its advantages and disadvantages. By combining the outputs of a GPS and an INS, the performance issues of both systems can be remedied. GPS/INS Computing System
Tightly Coupled INS/GPS PI PINS/GPS IMU Strap down Inertial Navigation Algorithm State Update ∆Vm VI VINS/GPS qI qINS/GPS ∆θm SDINS P V q PSAT Filter GPS Innovation Calculation meas . b GPS/INS Computing System
Kalman & Particle filter • Standard filter used in navigation systems is extended Kalman filter (EKF) • Disadvantages of the extended Kalman filter: • EKF is not an optimal estimator for non-linear systems • Optimized for statistical noise only • Particle filter can be used as an alternative to EKF, these to improve estimation's accuracy. • Particle filters is a sophisticated model estimation technique based on simulation using sufficient number of samples GPS/INS Computing System
Theoretical Solution • Implementing the tightly coupled INS/GPS navigation unit with the particle filter, according to algorithm developed in Technion. • The theoretical algorithm stages: GPS/INS Computing System
Project Goals GPS/INS Computing System
Our Project GPS Computing System
General Project will be performed in 2 stages. First part in this semester. Project will be performed by several work groups Our group will implement Particle Propagation and State Estimation stages in this first part. Both stages need to be performed each 0.01 sec, regardless of other stages performance. GPS Computing System
Group Project Goals – PART 1 GPS/INS Computing System
WorkingEnvironment GPS/INS Computing System
GidelPROCStar II • Up to 4 ALTERA Stratix II • 60 to 180 FPGAs • Five level memory structure • (over 2.5GB) • Typical system frequencies: • 100-300 Mhz. • Flexible clocking system. • Up to 695 available I/Os. • Up to 5 PSDBs (ProcStar II Daughter Boards): Camera Links, machine I/Os and other interfaces. • Expandable system: up to 96 DDR II I/Os between PROCStar II boards. • Up to 660 Gbits per second connectivity between FPGAs. GPS/INS Computing System
AlteraStratix II • 15,600 to 179,400 equivalent Logic elements • Adaptive logic module (ALM), maximizes performance and resource usage efficiency • Up to 9,383,040 RAM bits • High-speed DSP blocks provide dedicated implementation of multiply-accumulate functions. • Up to 12 PLLs (four enhanced • PLLs and eight fast PLLs) • per device. • Support for high-speed • external memory • Megafunctions support GPS/INS Computing System
AlteraQuartus II Provides a multiplatform design environment for all phases of FPGA design. GPS/INS Computing System
Design solutions GPS/INS Computing System
State Vector - X[1..18] GPS/INS Computing System
Design guidelines Constrains: • large amount of calculations • Limited hardware • real-time results Possible solutions: • Pipelining • Large amount of parallel calculation units Selected solution: • Max. Parallel processing • What can’t be parallel – will be Pipelined. GPS/INS Computing System
Solution – Top design xN Controller Weight vector Particles propagation unit State estimation unit Estimated State Vector [1..18] Extended State Vector [1..18] Extended State Vector [1..18] Extended State Vector [1..18] GPS/INS Computing System
Parallel VS. Pipeline • Considerations: • Max. parallel processes will result in Min. calculation time. • Number of parallel processes is limited by the hardware. • Not all calculations have to be parallel in order to comply with 100 Hz. GPS/INS Computing System
Parallel VS. Pipeline • Conclusions: • The number of L.E.’s (available on the FPGA) will determine the number of parallel processes in the “Particle propagation unit” and the “State estimation unit”. • To complete this number to N, we will pipeline the processes in those units. GPS/INS Computing System
Particles Propagation block GPS/NS Computing System
1 Particle Propagation block GPS/INS Computing System
State estimation block GPS/INS Computing System
q estimation block – N units GPS/INS Computing System
Not q components estimation block GPS/INS Computing System
Growth capability • Each design unit, deals with a number of particles. • The basic calculations in each unit, are designed for one particle and is then multiplied. • The same design can be implemented with “bigger” FPGAs, by increasing the number of multiplications and parallel processes. • This can result in lesser pipelines which means faster realization. • It can also implement bigger N. GPS/INS Computing System
Timeline GPS/INS Computing System
GANTT – PART A GPS/INS Computing System