BRAKE PARTICLE EMISSIONS TASK FORCE 1 Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS Theodoros Grigoratos, Marcel Mathissen, Christian Schmidt, Jarek Grochowicz, Rainer Vogt, Heinz Steven and TF1 Members 47th PMP IWG Meeting – Ispra (IT) – 17.05.2018

NON-EXHAUST PARTICLE EMISSIONS Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS WLTP Database Analysis (Concluded) Comparison of WLTP data with Existing Industrial Cycles (Concluded) Development of a first version of the new (WLTP based) and backup (LACT based) braking schedule (Concluded) Validation of the cycles - Round robin (reproducibility assessment on different dynos) (Deadline: March – April 2018) (Deadline: December 2018)

NON-EXHAUST PARTICLE EMISSIONS Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS FORD has concluded the development of the schedule in collaboration with Heinz Steven Technical details regarding the cycle will be presented in EuroBrake 2018 The cycle will become available to the public after its acceptance to the WEAR Journal (June 2018)

NON-EXHAUST PARTICLE EMISSIONS Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS i. What was the motivation for the development of the new cycle? Brake emission testing shall be done under representative driving conditions Currently available driving cycles used in the brake testing (e.g. Mojacar, LACT) were developed for other purposes and they need max brake temperature above 200ºC Mojacar average / max temperature: 125-175ºC / >250ºC LACT average / max temperature: 100-150ºC / >200ºC Reaching above temperatures require adequate driving pattern and vehicle payload As result, these procedures generate more wear and higher PN emissions compared to reality Need for a new standard cycle representing normal driving style and average payload

NON-EXHAUST PARTICLE EMISSIONS Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS ii. What was the procedure followed for the development of the new cycle? The WLTP database was used as a basis for the new braking schedule The database includes in-use driving data Five regions (EU, USA, India, Korea and Japan) Total mileage: 743.694 km 1 Hz data of vehicle speed, engine speed (for most vehicles), date and time of the day and trip number Should be company independent and by this find (world)wide acceptance

GENERATION OF THE CYCLE Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS GENERATION OF THE CYCLE Statistical distributions included in the development of the novel brake cycle*: Brake phase duration Brake phase distance Number of brake phases per km Data is complemented by an additional analysis of the WLTP in-use database for this study: Initial velocity Average deceleration Duration between brake phases

NON-EXHAUST PARTICLE EMISSIONS Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS iii. What were the main steps for the generation of the new cycle? Step 1: Analysis of statistical distributions Step 2: Candidate short trips from the WLTP were selected and put together to a first cycle Step 3: In order to match time between stops: stop phases or constant speed phases are inserted Step 4: Fine-tuning (replacement of segments, rectification: linear/decrease increase of decelerations/accelerations, etc.) Step 5: Division of cycle into 10 trips with 9 breaks (varying between 12-900 sec based on the WLTP data) to match average trip length of the WLTP

Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS NOVEL CYCLE 303 stops at a distance of 192 km 4h 24min duration Average speed of 44 km/h and maximum speed of 133 km/h Deceleration 0.49 – 2.18 m/s² (mean of 0.97 m/s²)

COMPARISON WITH LACT & WLTP STATISTICS Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS COMPARISON WITH LACT & WLTP STATISTICS The novel cycle closely matches the statistical distributions of the WLTP database not only for initial velocity, deceleration and brake duration but for all selected parameters

DEVELOPMENT OF THE CYCLE Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS DEVELOPMENT OF THE CYCLE Cycle reproduction at a vehicle level (Delayed – Concluded) Cycle reproduction on the brake dyno (Delayed – Concluded) Effect of cooling air velocity Effect of dyno inertia (vehicle mass) Effect of parasitic drag Correlation between the brake dyno and the vehicle (Concluded)

CYCLE REPRODUCTION AT A VEHICLE LEVEL Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS CYCLE REPRODUCTION AT A VEHICLE LEVEL Middle class vehicle (15” brakes: Sliding callipers, Grey Iron Discs and LowMet Pads) Additional pedal box, cycle monitor (trace of actual and target speed) to the co-driver

CYCLE REPRODUCTION AT A VEHICLE LEVEL Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS CYCLE REPRODUCTION AT A VEHICLE LEVEL Ambient temp of 8ºC – 18ºC and mean temp of 11ºC Disc temp during testing was ~50ºC (mean) and 128ºC max

CYCLE REPRODUCTION AT A BRAKE DYNO LEVEL Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS CYCLE REPRODUCTION AT A BRAKE DYNO LEVEL Identical brake parts as during vehicle testing Two set-ups were tested in the dyno Standard brake test setup with a horizontal cooling of 2200 m³/h Brake emission measurements setup with a cooling rate of 250 m³/h (enclosed measurement set-up) Tested the influence of the following parameters Parasitic drag (gear, rolling, aero) Vehicle mass (dyno inertia) Cooling air speed / temperature / humidity

Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS EFFECT OF COOLING RATE For the standard set-up (horizontal cooling of 2200 m³/h) dynamometer temperatures were found to be slightly lower compared to those recorded on vehicle

Horizontal cooling (2209 m³/h) Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS EFFECT OF COOLING RATE Cooling Condition Tmean [°C] TMax [°C] Horizontal cooling (2209 m³/h) 49 120 Enclosed measurement set-up (250 m³/h) 70 170 No cooling 86 197 VEHICLE 50 129 Temperatures under high flow conditions compare better with temperatures in the field Temperatures under low flow conditions are higher than in the field Risk of PN emissions overestimation

EFFECT OF PARASITIC DRAG Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS EFFECT OF PARASITIC DRAG Parasitic drag includes aerodynamic drag, rolling resistances, brake drag, etc. On average, 15% of the kinetic energy of a stop in the novel brake cycle is being dissipated by parasitic drag

EFFECT OF PARASITIC DRAG Development of a NEW REAL-WORLD BRAKING CYCLE FOR STUDYING BRAKE PARTICLE EMISSIONS EFFECT OF PARASITIC DRAG Low influence on average temperatures (52ºC vs. 49ºC) but higher on max temperatures (135ºC vs. 120ºC)

BRAKING TEST CYCLE – CURRENT STATUS FORD has developed the WLTP based profile in collaboration with Heinz Steven. The profile has being validated by FORD both on-road and on the dyno The novel cycle closely matches the WLTP database to simulate real-world driving conditions The selected profile will be used for bedding in of the pads. There is a practical issue as the proposed cycle is quite long

BRAKING TEST CYCLE – OPEN ISSUES Low flow dynamometer testing will lead to higher maximum temperatures than observed in the field. How can we reproduce correct temperature levels? Which temperature will be achieved for other vehicles (vehicle classes) How to adapt cycle to other vehicle classes? Influence of breaks between the trips Temperature level and cooling influence on other test setups for emission testing

BRAKING TEST CYCLE – NEXT STEP A round robin has been scheduled for the next months with the purpose of validating both braking schedules in terms of temperature. All labs participating in TF1 will take part and the round robin is expected to be completed by the end of 2018 A paper with the title “A novel real-world braking cycle for studying brake wear particle emissions” has been submitted to WEAR and is expected to be published soon

Any questions? You can find me at theodoros.grigoratos@ec.europa.eu