Team Members: Joshua Ax, Michael Krause, Jeremy Lazzari, Marco Peyfuss Faculty Advisors: Dr. Thomas Bradley, Dr. Sudeep Pasricha Graduate Research Assistants: Jamison Bair, Gabriel DiDomenico, Vipin Kukkala 04/24/2018
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Vehicle environmental impacts CO 2 emissions increasing [1] CAFE standards increasing [2] Market forces Hybrid sales are increasing [3] EcoCAR 3 Latest AVTC Camaro FS1 [1] "Sources of Greenhouse Gas Emissions", US EPA. [Online]. Available: https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions. [Accessed: 05- Sep- 2017]. [2] United States National Highway Traffic Safety Administration, "NHTSA and EPA Set Standards to Improve Fuel Economy and Reduce Greenhouse Gases for Passenger Cars and Light Trucks for Model Years 2017 and Beyond", 2017. [3] "Table 1-19: Gasoline Hybrid and Electric Vehicle Sales: 1999 2015", Rita.dot.gov, 2017. [Online]. Available: https://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_statistics/html/table_01_19.html. [Accessed: 05-Sep-2017]. Figure 1: Fuel Economy Increase from 2012 to 2025 [2] Figure 2: Hybrid Sales Increasing from 1999 to 2014 https://upload.wikimedia.org/wikipedia/commons/7/7a/cumulative_us_hev_sales_by_year_1999_2009.png 3
Software-in-loop (SIL) model Fuel economy model Basic controls developed Vehicle-in-loop (VIL) model CAN communication Vehicle start-up logic Rudimentary charge-sustaining control strategy Figure 3: CSU Camaro Driving at Year 3 Competition 4
Parallel Hybrid P2 architecture Plug-in battery E85 flex-fuel engine 8 speed transmission Operating modes Electric Vehicle (EV) Charge Sustaining (CS) Charge Increasing (CI) Performance Figure 4: CSU Camaro FS1 Powertrain Architecture 5
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Year 3 SIL and VIL Update SIL Controller EV Mode CS Mode CI Mode Performance Mode First Semester Refine if Necessary Testing in SIL Testing in SIL Testing in SIL Testing in SIL Testing in SIL all Together Compile in VIL Second Semester Testing in Vehicle 7
Three major goals for the vehicle control strategy Maintain consumer acceptability Maximize energy efficiency Minimize environmental impact Other considerations Safety Drivability Competition events and requirements 8
Four Vehicle Modes Electric Vehicle (EV) Charge Sustaining (CS) Performance Charge Increasing (CI) Consumer Acceptability CI Mode Performance Mode EV Mode Emissions and Energy Consumption CS Mode Key Design Elements Braking and coasting regeneration Torque split strategy for optimal efficiency Design for drivability Safety cases 9
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Vehicle switches between modes based on SOC and driver input Within each driving mode, there are four operating states Idle Speed control when at a stop Drive Torque split algorithm Coast Aggressive motor regeneration Brake Pedal modulated motor regeneration Coast and brake states are identical between all driving modes Drivability and safety design features 11
EV Mode Idle Motor only idle Drive Motor meets the powertrain requested torque T motor = T powertrain Charge depleting Engine is never turned on Performance Mode Idle Motor and engine idle Drive Engine is the preferred actuator while driving T eng = 0.95 T powertrain T motor = T powertrain T eng Slightly charge depleting Engine is always on 12
CS Mode Idle Motor and engine idle Drive Torque split approximates a minimal power function Below 120 Nm of desired torque T eng = T powertrain + T LV T motor = T powertrain T eng Above 120 Nm of desired torque T eng = T IOL T motor = T powertrain T eng Engine is turned on and off to save fuel Includes an energy-based engine warmup algorithm to reduce criteria emissions Figure 5: Minimal Power Function 13
CI Mode Stationary fast charge Charging while moving Idle Motor and engine idle Drive The engine is the primary driving source T eng = T powertrain + T LV + T charge T motor = T powertrain T eng Engine is never turned off in order to force charge increasing behavior 14
Torque shaping for lash control Transmission and differential Excessive jerk negatively affects the driver Shift management Torque cuts are required on shifts Implemented an inertia compensation algorithm T HEV = J HEV J stock T stock Engine bump start smoothing Architecture does not include a starter motor Motor torque was increased during engine starts 15
Motor direction Motor must always be spinning CW Regenerative torque Must be less than 0 Nm during coasting/braking maneuvers Transmission shift state Estimated gear must match up with shift lever Thermal systems Each component must stay within its thermal limits 16
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Data comes from Christman Airstrip and chassis dynamometer testing at the Transportation Research Center (TRC) Figure 6: Christman Airstrip Testing Figure 7: Testing at the TRC 18
Goal Maintain consumer acceptability Maximize energy efficiency Minimize environmental impact Objective Meet performance specifications expected of a sports car Control electrical system to operate as efficiently as possible Optimize torque split strategy for blended modes Operate the engine as efficiently as possible Method of Measurement CSU Target EcoCAR 3 Requirement Preliminary Result 0-60mph time 5.9 sec 7.9 sec 7.4 sec 50-70mph time 7.3 sec 9.9 sec 3.8 sec EV mode range 25 mi N/A 22.4 mi EV mode energy consumption Total vehicle range CS mode fuel economy UF weighted GHG emissions 100 mpgge N/A 93.5 mpgge 200 mi 150 mi 174 mi 35 mpgge N/A 29.6 mpgge 225 g GHG/km 250 g GHG/km 243 g GHG/km 19
Torque Shaping Engine Bump Starts Shift Management 20
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What didn t work and what went wrong Open loop control Testing limited by vehicle down-time What did work and what went right Multi-year projects need multi-year members Support from professional and academic mentors Utilizing different team members strengths 22
Future work CS mode optimization using actual engine and motor data Making SIL more robust Leveraging HIL setup Final testing before competition at Honda R&D Final competition! 23
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