STATE OF MARYLAND BALTIMORE CENTRAL LIGHT RAIL LINE. To Evaluate Ride Quality for Higher Unbalance Speeds on Curves

Transcription

1 STATE OF MARYLAND MASS TRANSIT ADMINISTRATION BALTIMORE CENTRAL LIGHT RAIL LINE TEST PROGRAM To Evaluate Ride Quality for Higher Unbalance Speeds on Curves Narayana Sundaram ENSCO, Inc. August 31, 2010

2 Summary Objective - Compare carbody accelerations measured through curves to ride comfort subjective evaluations Tests conducted on Baltimore LRT - April 18, 2010 Ridemeter measurements - lateral and vertical accelerations on carbody floor Five curves on northbound track, and five curves on southbound track tested at various speeds

3 Test Route

4 MTA Baltimore LRT Car #5013 4

5 Ridemeter Instrumentation 5

6 Carbody Lateral Acceleration, Northbound Run 12

7 Carbody Lateral Acceleration, Southbound Run 14 7

8 Measured Lateral Accelerations 0.30 Steady-State Lateral Acceleration vs Cant Deficiency 0.25 Curve NE18 Curve NE19 ation [g] Acceler Proposed Limit Curve NE20 Curve NE23 Curve NE25 Curve NW22 Curve NW21 Curve NW Curve NW17 Curve NW Cant Deficiency [inches]

9 Example Static Lean Test Results 14,000 An Example - Static Lean Test Wheel UnLoading Wheel Loa ad (pounds) 13,000 12,000 11,000 10, ,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1, % Remaining Cant Deficiency (inches)

10 Example Static Lean Test Results Corresponding Example Axle and Carbody Steady State Lateral Accelerations Acceleration Expected on Axles Acceleration Expected on the Carbody Accelera ation (g) Cant Deficiency (inches) 10

11 Measured Lateral Accelerations Steady-State Lateral Acceleration vs Cant Deficiency Curve NE18 Curve NE19 Accelera ation [g] Proposed Limit Curve NE20 Curve NE23 Curve NE25 Curve NW22 Curve NW21 Curve NW Curve NW17 Curve NW Cant Deficiency [inches] 11

12 Conclusions Maximum Steady State lateral acceleration measured was 0.28 g. More research needs to be conducted in this area to confirm use of higher speeds in curves

13 Thank you for your attention! ti Questions, please?

14 Baltimore, Maryland Central Light Rail Line Lateral Acceleration Testing

15 Test Objective Evaluate lateral acceleration vs. ride comfort Current standard: 0.10g max (6 Eu) Proposed: 0.15g max (9 Eu) For Embedded Track

16 Lateral Acceleration Math g = E u E = V 2 D E a + (E u E r ) = V 2 (5730/R) Speed (V) which establishes the unbalance For a specific Curve Radius (R) With a specific Actual superelevation (E a ) Using a vehicle with specific suspension (roll angle, E r ) Produces a specific lateral acceleration g (E u ) That people subjectively perceive as ride comfort

17 Getting Organized Test planning A year of meetings for: Safety planning Selecting test curves Conducting preliminary measurements Coordinating instrumentation Arranging participants

18 Track schematic

19 Northbound Starting Point

20 Curve NW 16 and NE 18

21 Curve NW 17 and NE 19

22 Curve NE 20

23 Curve NE 25

24 North Ave. Station

25 Preliminary Measurements Actual superelevation, E a Vehicle roll angle, E r

26 Test Speeds Track Curve g Speed g Speed g Speed g Speed N/W Track Curve g Speed g Speed g Speed g Speed NE

27 Speed Signs FRONT BACK COVER

28 Ride Quality Rating Scale 0 Nothing Noticeable 1 Just Noticeable 2 Noticeable 3 Pronounced 4 Very pronounced but not uncomfortable 5 Strong & Slightly Uncomfortable 6 Rather Uncomfortable

29 Ride Quality Data Collection Form

30 The Test Vehicle

31 Car Interior

32 Recording Ride Quality

33 ENSCO s Accelerometer

34 Onboard Recording Equipment

35 File 1 Southbound Speed Chart

36 File 8 Northbound Speed Chart

37 Ride Quality Ratings Run No. 4 Nominal Lateral Accleration: 0.175g Curve Number Rater NW22 NW21 NW18 NW17 NW16 NE25 NE23 NE20 NE19 NE18 2D D D D D D D D D D D D D D Avg

38 Lateral Acceleration vs. Ride Quality Curve No. Design Radius Actual Ea File 1 Actual appx 0.1g File 2 Comput ed Avg Actual appx 0.125g File 7 Comput ed Avg Actual appx 0.15g File 8 Compute d Avg Actual appx 0.175g Compute d Ea (Avg'd) V g RQ V g RQ V g RQ V g RQ NW IRR NW IRR IRR IRR NW IRR NW IRR IRR IRR NW IRR Avg File 3 File 4 File 5 File 6 NE IRR IRR NE IRR NE IRR IRR IRR NE IRR NE Curves marked IRR had irregular speeds through the curve and no avg speed could be assigned Computed g values are based on speed and do not include vehicle roll angle effect Ride Quality values are average of 15 to 18 riders judgments with high and low values excluded from average

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40 What s Next Further Research on Lateral Acceleration Research on Spirals

41 Many Thanks to: Maryland Transit Administration William Parks, Chief, Tk & Str Engrg, MTA Fletcher Hamilton, CLRL Dir of LRT operations, MTA Mike Wiedecker, Proj Mgr, LRT Opns, MTA Stan Snead and Earl Lewis, Safety Office, MTA Martin Schroeder, Chief Engr. APTA Bill Moorhead, Chair, APTA/AREMA Embedded Track Work Group and all the Volunteer Participants i t ENSCO (accelerometer instrumentation) Narayana Sundaram, ENSCO