Pavement Structural Evaluation at the Network Level: Final Report

APPENDIX A. DEVICE MANUFACTURERS' QUESTIONNAIRES AND INTERVIEWS

To augment the project literature review findings, questionnaires were developed and sent to the device manufacturers as well as owners and users of the devices. Interviews were also conducted to follow up with specific questions or to pursue clarification. The completed questionnaires as well as highlights from the interviews are contained in this appendix.

Name of moving deflection device: ______________

Name of person completing questionnaire: _____________

Date questionnaire was completed: ______________

I. Device Information for Analysis

1) Please briefly describe the measurement concepts and technology basis of your device. Alternatively, please attach any technical brochure you may have that includes that information.

________________

2) Please summarize the improvements to the device in the last 3 years.

_______________

3) In terms deformation parameters measured,

a) How many deformation points are reported for each measurement (loading point) at this time (i.e., can you define a deflection bowl)? ________

b) What are the offsets from the load to different measurement points? __________

c) If less than three deformation points are reported, what is the potential of increasing the number of points reported in the near future and how many points will be feasible? ____________

4) In terms of loads applied to pavement,

a) Is it possible to vary the load applied to pavement? Yes __ No X

If yes, specify the range ______ , and specify how _______ .

If no, do you intend to add this feature? and (if applicable) specify the load range you feel is feasible _________________

b) Do you measure and report applied (instantaneous dynamic wheel) load at this time?

Yes_ No X

If no, what is the potential of measuring and reporting applied load in the near future? ____________

5) In terms of geospatial information at the time of testing,

a) Do you use a GPS unit? Yes X No__

b) What geospatial information is included in the file (can we superimpose on Google^® maps, etc.)? _____________

6) Is the device equipped with temperature gauge? Yes No

a) If yes, specify the range ______, and specify how temperature is measured and reported. ______

b) If no, do you intend to add this feature in the near future? _________

7) Is your device equipped with other measuring technologies (e.g., GPR, video, roughness measurement, etc.)? Yes ___ No X

a) If yes, specify the technology(ies) and parameters reported. ________

b) If no, do you intend to add any auxiliary technologies in the near future? (Please explain.) ________

8) What is the technically feasible range of speeds that your device provides valid measurements (as opposed to safety-related)?

Max. speed (e.g., when data acquisition cannot keep up) _________

Min. speed (e.g., not enough deformation amplitude), if any __________

9) What is the recommended distance between successive readings? _______

Can the user define the distance between successive readings? Yes X No ___

If yes, specify min. ____ and max. _____

10) What is the recommended spatial averaging distance of the deformation parameters? ________________

Can the user define the spatial averaging distance? ________________

11) What type of spatial averaging algorithm is used? ___________

12) What types of pavement structures can be tested with confidence using the device (flexible, rigid, or semi-rigid)? If applicable to pavements other than flexible, are there any operational limits (open-ended question)? _____________

II. Device Information for Operation

13) Have you established written test protocols for the device (including pre-testing activities, test protocol during data collection, and post-testing activities)? Yes __ No X

a) If yes, please attach the document. ___________

b) If no, please explain how typically the device is operated. _________

14) Have you established a written calibration process for the device? Yes __ No X

a) If yes, please attach the document. _________

b) If no, please explain how the accuracy of the measurements is ensured. ________

15) Does pavement texture or other surface characteristics (dark/light/moist pavement) impact your deformation measurement concept/technology? Yes X No __ If so, do you account for it in your measurements/analyses?

a) If yes, please explain how:

a) During measurements __________

b) During data analyses ___________

b) If no, please explain how the accuracy of the measurements is ensured. _________

16) Do you consider the impact of pavement condition (e.g., roughness, cracking, and rutting) on your measurements/analyses? Yes X No ___

a) If yes, please explain how:

a) During measurements___________

b) During data analysis ___________

b) If no, please explain how the accuracy of the measurements is ensured. ___________

III. Device Information for Evaluation

17) The deformation sensors used are _____ manufactured by _____ .

a) Under ideal conditions, the stand-alone sensor has the following characteristic:

• Nominal calibration factor is _____ xx/volt
  
  
• Precision is _____
  
  
• Accuracy is _____
  
  
• Effective range is between (min.) _____ and (max.) _____

b) When installed in the system, the sensor has the following characteristic during testing:

• Precision is _________ as determined using the following process _________
  
  
• Accuracy is _________ as determined using the following process _________
  
  
• Effective range is between (min.) ____and (max.)____ as determined using the following process _________.

18) The load sensors used are ______ manufactured by _________ .

a) Under ideal conditions, the stand-alone sensor has the following characteristic:

• Precision is _________
  
  
• Accuracy is _________
  
  
• Effective range is between (min.)____ and (max.) ____
  
  

b) When installed in the system, the sensor has the following characteristic during testing:

• Precision is _______ as determined using the following process _______
  
  
• Accuracy is _______as determined using the following process _______
  
  
• Effective range is between (min.) _____ and (max.) _____ as determined using the following process _______

19) The electronics used have the following generic information.

a) A/D board digitizes at ______ (12, 16, or 24) bits.

b) Amplifiers are used to amplify the signals by ______ times for deformation and times for load.

c) Signals are subjected to a (low, high, or band pass) filter(s) with the following characteristics:

• Deformation:
  
  
• Load:
  
  

d) The rawest form of data saved by the device are in the form of (raw voltage output, specified processed data at each measurement point, average of __ measurements, etc.):

• Deformation: _________
  
  
• Load: _________
  
  
• Distance: _________
  
  

e) The data that can be shared with the research team are (mark all that apply):

__ Raw voltage outputs.

__ Specified processed data at each measurement point.

__ Average of measurements.

X Other (please specify):

f) What is the electronic format of the reported data to client? _________ (Please attach an example).

g) Could you please explain what general algorithm used to obtain the data for client report (item f) from the raw data (item d)?

• For Deformation: ____________
  
  
• For Load: ____________
  
  
• For Distance: ____________

h) Is your device equipped with external ports so that the research team can record the sensor outputs independently?

• For Deformation Sensors: Yes ___ No X
  
  
• For Load Sensors: Yes___ No X

i) If yes, do they allow the research team to collect data with them? ____________

People Interviewed: Doug Steele, David Hein, and William Vavrik

Date Interviewed: January 14, 2013

Interview Conducted by: Gonzalo Rada, Soheil Nazarian, Nadarajah Sivaneswaran (Siva), and Beth Visintine

• Individual deflection readings at 0.5-inch intervals.
  
  
• Raw data is in binary format.
  
  
• No averaging during initial laser processing of measurements.
  
  
• RWD has four sensors to collect deflection.
  
  
• Second deflection (D₁₅) for diagnostic purposes and is 18 inches apart.
  
  
• Vibration of beam not measured; this goes into variability of lasers and aggregating data takes this out.
  
  
• Different forms of processing have not [really] been tried (i.e., filtering, moving average, moving standard deviation, etc.).
  
  
• Bouncing of truck (sinusoidal cycle) adds noise but this is taken out by average.
  
  
• Frequency of texture is main cause of noise in deflection.
  
  
• Able to collect data down to 5 mi/h.
  
  
• Collect data in temporal domain; based on DMI, use reading every 15 mm regardless of speed to transfer to distance domain.
  
  
• Do not measure dynamic load or tire pressure; measure static load and assume constant. Varying dynamic load can add to variability with texture.
  
  
• Independent of system, will allow to add tire pressure measuring device.
  
  
• Need work plan for field experiment to determine the RWD cost. Will sign a letter of commitment subject to approval of work plan.
  
  
• Mentioned Kansas has instrumented sections and to contact Rick Miller.
  
  

Name of moving deflection device: __________

Name of person completing questionnaire: __________

Date questionnaire was completed: __________

I. Device Information for Analysis

1) Please briefly describe the measurement concepts and technology basis of your device. Alternatively, please attach any technical brochure you may have that includes that information.____________

2) Please summarize the improvements to the device in the last 3 years.__________

3) In terms deformation parameters measured:

a) How many deformation points are reported for each measurement (loading point) at this time (i.e., can you define a deflection bowl)? _________

b) What are the offsets from the load to different measurement points? ________

c) If less than three deformation points are reported, what is the potential of increasing the number of points reported in the near future and how many points will be feasible? _____________

4) In terms of loads applied to pavement:

a) Is it possible to vary the load applied to pavement? Yes X No ___

If yes, specify the range______, and specify how ______.

If no, do you intend to add this feature? and (if applicable) specify the load range you feel is feasible _____________

b) Do you measure and report applied (instantaneous dynamic wheel) load at this time?

Yes X No ___

If no, what is the potential of measuring and reporting applied load in the near future? _____________

5) In terms of geospatial information at the time of testing:

a) Do you use a GPS unit? Yes X No ___

b) What geospatial information is included in the file (can we superimpose on Google^® maps etc.)? _________

6) Is the device equipped with temperature gauge? Yes X No ____

a) If yes, specify the range , and specify how temperature is measured and reported.

b) If no, do you intend to add this feature in the near future?

7) Is your device equipped with other measuring technologies (e.g., GPR, video, roughness, measurement, etc.)? Yes X No ____

a) If yes, specify the technology(ies) and parameters reported. _________

b) If no, do you intend to add any auxiliary technologies in the near future? (Please explain.) ___________

8) What is the technically feasible range of speeds that your device provides valid measurements (as opposed to safety-related)?

Max. speed (e.g., when data acquisition cannot keep up) ________

Min. speed (e.g., not enough deformation amplitude), if any ____________

9) What is the recommended distance between successive readings? __________

Can the user define the distance between successive readings? Yes ___No X

If yes, specify min.______ and max._______

10) What is the recommended spatial averaging distance of the deformation parameters? ______________

Can the user define the spatial averaging distance? ____________

11) What type of spatial averaging algorithm is used? ________________

12) What types of pavement structures can be tested with confidence using the device (flexible, rigid, or semi-rigid)? If applicable to pavements other than flexible, are there any operational limits (open-ended question)? _____________

II. Device Information for Operation

13) Have you established written test protocols for the device (including pre-testing activities, test protocol during data collection, and post-testing activities)? Yes X No___

a) If yes, please attach the document. _________

b) If no, please explain how typically the device is operated. _____________

14) Have you established a written calibration process for the device? Yes X No___

a) If yes, please attach the document. ______

b) If no, please explain how the accuracy of the measurements is ensured. ______

15) Does pavement texture or other surface characteristics (dark/light/moist pavement) impact your deformation measurement concept/technology? Yes X No___ If so, do you account for it in your measurements/analyses?

a) If yes, please explain how:

a) During measurements ______

b) During data analyses ______

b) If no, please explain how the accuracy of the measurements is ensured. ______

16) Do you consider the impact of pavement condition (e.g., roughness, cracking, and rutting) on your measurements/analyses? Yes ___ No ___

a) If yes, please explain how:

a) During measurements ______

b) During data analyses ______

b) If no, please explain how the accuracy of the measurements is ensured. ______

III. Device Information for Evaluation

17) The deformation sensors used are ______ manufactured by ______ .

a) Under ideal conditions, the stand-alone sensor has the following characteristic:

• Nominal calibration factor is ______ xx/volt
  
  
• Precision is ______
  
  
• Accuracy is ______
  
  
• Effective range is between (min.) ______ and (max.) ______
  
  

b) When installed in the system, the sensor has the following characteristic during testing:

• Precision is ______ as determined using the following process ______
  
  
• Accuracy is ______ as determined using the following process ______
  
  
• Effective range is between (min.) ______ and (max.) ______ as determined using the following process ______
  
  

18) The load sensors used are ______ manufactured by ______

a) Under ideal conditions, the stand-alone sensor has the following characteristic:

• Precision is ______
  
  
• Accuracy is ______
  
  
• Effective range is between (min.) ______ and (max.) ______
  
  

b) When installed in the system, the sensor has the following characteristic during testing:

• Precision is ______ as determined using the following process
  
  
• Accuracy is ______ as determined using the following process
  
  
• Effective range is between (min.) __ and (max.) ___ as determined using the following process ______

19) The electronics used have the following generic information:

a) A/D board digitizes at ______ (12, 16, or 24) bits.

b) Amplifiers are used to amplify the signals by ______ times for deformation and ______ times for load.

c) Signals are subjected to a (low, high, or band pass) filter(s) with the following characteristics:

• Deformation: ______
  
  
• Load: ______

d) The rawest form of data saved by the device are in the form of (raw voltage output, specified processed data at each measurement point, average of __ measurements, etc.):

• Deformation: ______
  
  
• Load: ______
  
  
• Distance: ______

e) The data that can be shared with the research team are (mark all that apply):

• __ Raw voltage outputs.
  
  
• __ Specified processed data at each measurement point.
  
  
• __ Average of measurements.
  
  
• __ Other (please specify):

f) What is the electronic format of the reported data to client? ______ (Please attach an example).

g) Could you please explain what general algorithm used to obtain the data for client report (item f) from the raw data (item d)?

• For Deformation: ______
  
  
• For Load: ______
  
  
• For Distance: ______

h) Is your device equipped with external ports so that the research team can record the sensor outputs independently?

• For Deformation Sensors: Yes __ No __
  
  
• For Load Sensors: Yes __ No __

i) If yes, do they allow the research team to collect data with them? ______

People Interviewed: Jørgen Krarup, Leif Grønskov, and Louis Pedersen

Date Interviewed: January 15, 2013

Interview Conducted by: Gonzalo Rada, Soheil Nazarian, Nadarajah Sivaneswaran (Siva), and Beth Visintine

• Have fixed data issue with minimum amount of filtering.
  
  
• Want us to limit the technical information that we include in the report.
  
  
• There is a phase issue within the Doppler sensors.
  
  
• The TSD manufacturer is bringing one of their units over to the US at their expense. Project will pay for data collection. FHWA to look into issue with customs and see if there are any workarounds.
  
  
• The calibration of the sensor angles is important.
  
  
• Measure load within 0.5 kg.
  
  
• New Doppler sensors can be moved (unlike TSD version the United Kingdom Transportation Research Library has). Therefore, can place sensors before and after joint to determine load transfer.
  
  
• Issue with horizontal curves have been addressed (based on beam movement), but the project team should consider including curves within work plan.
  
  
• Willing to provide raw data once they know how the project team will use it. This is not an issue of wanting to hide anything, but want to make sure that it is being used properly (for a specified limited section).
  
  
• TSD includes measurement of IRI.
  
  
• Speed can be an issue if the sensor height is not properly adjusted. Sensor still works, just less precise. If this happens, the reported data rate drops. This issue has been addressed in the new system.
  
  
• Do not recommend measuring below 30 km/h, as this is to avoid the viscoelastic response or minimizes it.
  
  
• Agreed to have a letter of commitment by mid-February 2013.