Gurkan Erdogan. Department of Mechanical Engineering University of Minnesota

Transcription

1 PART - Frictio Coefficiet Measureet Syste for Witer Maiteace Vehicles Fuded by MDoT Gurka Erdoga Departet of Mechaical Egieerig Uiversity of Miesota

2 Obective Develop a o-board frictio easureet syste for a sow plow Cotiuously estiate tire-road frictio coefficiet while the sowplow travels Autoate applicatio of sad, salt or deicig aterial to the roadway Track ad provide estiated frictio values to the vehicle operator Gurka Erdoga, Ph.D.

3 Beefits of the Developed Techology Reduces uecessary cheical applicatio to roads Causes iial eviroetal daage waters, vegetatio ad trasportatio ifrastructure Reduces witer aiteace costs Provides sigificat cost savigs for trasportatio agecies Siplifies the traiig of fresha operators Icreases road safety Esures roads are safe usig a obective criterio for witer aiteace operatio. Helps operators to focus o safe sowplow drivig ad sow clearig, without worryig about applicator cotrol. Protects trasportatio agecies fro possible law suits Gurka Erdoga, Ph.D.

4 Traditioal vs. New Syste Norse Meter Syste coercially available Uses a actuator to brake ad skid the additioal wheel o the roadway at tied itervals Requires a dedicated operator. New Syste Geerates a cotiuous force sigal eablig the desig of a autooous syste Requires iial actuator effort No dedicated operator. Gurka Erdoga, Ph.D.

5 Theoretical Backgroud: Tire-Road Frictio Coefficiet Slip Agle α δ θ V Lateral Tire Force F y α ρ α F z Tire - Road Frictio Coefficiet F y α ax ρ op µ F z F z F y µ F b µ a filtered Gurka Erdoga, Ph.D.

6 Desiged Frictio Measureet Syste Gurka Erdoga, Ph.D.

7 Available Tie for Sigal Processig Available Tie L V Gurka Erdoga, Ph.D.

8 Traditioal Low Pass Filter LPF Perforace Measureet oise ostly cetered about 0 Hz bad: Vibratios coig fro the road.5 Hz bad: Fluctuatios due to low freq vibratios ad the chage i cotact patch Traditioal LPFs caot reove the low frequecy oscillatios at about.5 Hz while also satisfyig the target tie delay liit. [db] Gurka Erdoga, Ph.D.

9 Techical Challeges Quick detectio of sigificat chages i the lateral force. Reectio of high oise levels i easureets. Eliiatig the effects of truck aeuvers Steerig Maeuver Acceleratio & Deceleratio Maeuvers Gurka Erdoga, Ph.D.

10 New Vibratio Cacellatio Algoriths Two algoriths are proposed based o the acceleroeter sigal; Cross-Correlatio Based Filterig Algorith Adaptive Feedforward Filter Load Cell Acceleroeter Gurka Erdoga, Ph.D.

11 Cross-Correlatio Based Filterig Algorith. Filter out the load cell ad the acceleroeter sigals for the oise at frequecy bads higher tha 0 Hz.. Shift acceleroeter sigal wrt the load cell sigal i order to achieve eve higher correlatio. C yf P 3 p p { 3,,,0,,,3 } σyf p σyy p σff p { p: p P & C p axc p } yf [ ] 3. Add load cell sigal to acceleroeter sigal for reovig the fudaetal oise copoet cetered at 0 Hz. p k p µ filtered f µ f µ y yf Gurka Erdoga, Ph.D.

12 Adaptive Feedforward Filter Filter Iputs: u, u, u,..., u l Filter Coefficiets: Filter Outputs:, h, h 3,..., h l h M h,..., y hu l l Gurka Erdoga, Ph.D. l M 4

13 Adaptive Feedforward Filter Error : Square Error : l l l u h d y d e e ξ Square Error : Gradiet of Error Square: e ξ [ ] e e ξ T h e h e h e e L L [ ] T u u u e L L Gurka Erdoga, Ph.D.

14 Adaptive Feedforward Filter e u h h ρ d e h u T e u u u h h h h h h M M M M M M ρ Gurka Erdoga, Ph.D.

15 Adaptive Feedforward vs. Cross-Correlatio at 30 [ph] Gurka Erdoga, Ph.D.

16 Adaptive Feedforward vs. LPF at 30 [ph] σ σ ~300s σ 0.04 Gurka Erdoga, Ph.D. σ 0.05

17 Adaptive Feedforward vs. Cross-Correlatio at 35 [ph] Gurka Erdoga, Ph.D.

18 Adaptive Feedforward vs. LPF at 35 [ph] σ 0.05 σ ~300s σ 0.04 Gurka Erdoga, Ph.D. σ 0.0

19 Test Eviroet Gurka Erdoga, Ph.D. Applicator

20 Movie Frictio Based Applicator Cotrol Syste Perforace Gurka Erdoga, Ph.D.

21 Cacellatio of Lateral Vehicle Maeuvers Load Cell Gurka Acceleroeter Erdoga, Ph.D.

22 Eliiatig the Effects of Acceleratio & Deceleratio The logitudial tire force is aliged with the vertical hige. Acceleratio/deceleratio aeuvers do ot disturb the easureets. Gurka Erdoga, Ph.D.

23 Other Perforace Tests Applicator Delays at Differet Sowplow Speeds Applicator Delay Sigal Processig Algorith Delay Mappig of Road Frictio Data M-Road Test Eviroet Gurka Erdoga, Ph.D.

24 Zero Velocity Applicator ad Total Syste Delays Gurka Erdoga, Ph.D.

25 Mappig of Road Frictio Data Gurka Erdoga, Ph.D.

26 LRT Gurka Erdoga, Ph.D.

27 QMF : N x y i i RMS y σ µ K K K x K K x K K x x K x y i i i i i i i i i i i µ σ µ µ µ µ µ µ µ Gurka Erdoga, Ph.D.