Ram Racing CSU Formula SAE

Transcription

1 Ram Racing 2016 CSU Formula SAE

2 Background/History Colligate Electric Racecar design competition Ram Racing was established in nd iteration of Formula SAE Electric Competition Static events Design Judging, Cost Report, Project Presentation, Technical Inspection Dynamic events Acceleration, Skid pad, Autocross, and Endurance

3 Problem Statement Design all systems independently May have professional advice but all designs must be Student drafted Acquire data for future teams Battery temperature characteristics, discharge time, and charge time Forces acting on the car and driver Optimum gears ratios for each event

4 Objectives and Constraints All designs are acceptable according to Formula SAE requirements Pass technical inspection System should lend itself to evolution design Remain within budget Fundraising, Donations, Sponsorships

5 Design Summary Design Control Circuits Reliable, Simple, and easily maintained Years after wont have to worry about these circuits Design Battery 300VDC, Lithium Cobalt Oxide 10Ah at 15C discharge Implement Real-time Microcontroller CAN communication Data allocation

6 Mechanical Design Summery Spaceframe chassis EMRAX 207 motor connected to differential via chain Interchangeable rear sprockets to vary gear ratios Batteries cooled by forced airflow from sidepods and exhaust fans (if needed) Key Improvements Improved rear suspension New battery case New motor mount Redesigned sidepods

7 Design Decisions Safety and Control Circuits 12VDC system, in series switches and relays controlled by parallel systems (IMD, BMS, etc ) Ladder logic Robust, reliable, simple, and proven 12 VDC coil, 10 A contact, small (15mm cubes), automotive grade Real time Microcontroller Atmel 32-bit AVR UC3 AT32UC3C pin 5VDC-12VDC power input Dual CAN Communications, Local Network Interfaces One 4-channel PWM controller, one 16-channel ADC, two 12-bit DAC, 123 GPIO pins Atmel studio IDE, C programming

8 Design Decisions CAN Protocols Encoder protocols Accelerator 10% Accuracy, voted output, pass to motor control Brake plausibility Data logging Speeds G-forces Accelerator is not outputting while brakes are applied Battery states Motor states Pedal positions

9 Design Decisions High voltage Controller Rinehart PM-100DX Used From Future Evolutions May Not Use VDC IN, 300VAC OUT, 250ADC Continuous, 350ADC P-P Not a Choice of the Present Team (Cost Consideration) Motor EMRAX 207 (208) 300VAC, 140 Nm (103 ft-lb), 160ARMS, Weight 20.7 lbs Chosen for Cost, Size, Weight, Standardization

10 Design Decisions Battery cells Melasta SLPB VDC nominal, 10Ah 15C (150A) continuous discharge rate, 20C (200A) max. 72 series configuration for 300VDC Battery Management System Orion controller 108 cell voltage sensors Cell voltage balancing Dual CAN Communications Thermistor Expansion Module 80 temperature sensors CAN bus communication

11 Budget Predicted Initial Budget Simplified Budget Total Raised: $7,500 Account balance: $1,300 Need to raise: $6,500

12 At-risk Items and Mitigation Plan Most At-Risk Components (Electrical) Motor (Heating/Power), Battery(Heating), MSC (Component Failure) Formula = (Rank/40)*R.O.O.* D 1,.6,.315 (Weighted Risk) High Risk Due to High Occurrence Not Indicative of Catastrophic Fault but working Limitations Performance Impacted Mostly ESA and FMEA have lead to realization of possible subsystem/battery failure

13 Validation (Design Evaluation, Prototype Evaluation) Electrical Validation Benchtop testing Test-to-Validate Approach Test integrated vehicle circuit before installation Functional Testing in Vehicle

14 Work-plan Purchase the Orion Battery Management System Bench-test circuits Rolling chassis by 1/1 Assemble wiring harness on chassis Battery complete by 2/1 Completed car for testing by 3/14 Test drive and collect data for future improvements Complete tested car by E-days

15 Questions?

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17 Logic Schematic and Diagram

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21 Electrical FMEA Mechanical FMEA