Re ECF Project: 2007-11

Project Title: Developing a fully automated Close-Proximity vehicle for measuring tyre/road noise

Applicant: The Hong Kong Polytechnic University (Dr. HUNG Wing-tat)

Total Approved Grant: $1,768,380

Duration: 1/1/2009 to 30/9/2010

Project Status/Remarks: Completed

The main purposes of this project are:

  1. to demonstrate the proper application of tyre/road measuring method as stipulated in the draft ISO11819-2 locally in Hong Kong;
  2. to develop a full automated CPX tyre/road noise measuring vehicle which can perform efficient noise measuring, especially in the local narrow road configurations of Hong Kong;
  3. to devise experimental setups to perform certification tests for the CPX tyre/road noise measuring vehicle necessary to meet all the requirements as specified in the draft ISO11819-2 except that the test tyre may be a locally available tyre;
  4. to perform road worthiness tests and trial runs for this CPX tyre/road noise measuring vehicle;
  5. to develop a manual for the development and use of this CPX tyre/road noise measuring vehicle in Hong Kong; and
  6. to disseminate all technological materials obtained from this project through a dedicated web-site and training programmes to local engineers and professionals

Summary of the Findings/Outcomes:
A two-wheel tyre/road noise measuring assembly with an acoustic enclosure was designed and fabricated based on the CPX methods as stipulated in the draft ISO CD 11819-2. The assembly is fully automated with tailored made cable connections to a light goods vehicle which is equipped with all sensing instruments needed to support the tyre/noise measurements. Apart from measuring the tyre/road noise with two microphones at one test wheel, it also measures instantaneous air temperature, road surface temperature, driving speed, GPS locations and vibrations. Certification tests on the assembly according to the ISO 11819-2 were performed to ensure the measurements of tyre/road noise and other parameters comply with acceptable professional standards. The certification results were satisfactory.

This new tyre/road noise measuring assembly was used to measure tyre/road noise of over 30 road surfaces comprising 10 low noise road surfacing sections, 5 concrete sections, 5 stone mastic asphalt sections, 5 friction course sections and 5 wearing course with three different types of tyres. The results indicate that the measured sound pressure levels are in line with results obtained from similar studies elsewhere. The assembly can effectively and efficiently assess acoustic characteristics of both the road surfaces and tyres.