SENSORS ADD MORE SAFETY
By TA News Bureau:
As research scientist with the Guangdong (China)-based Wanli Tire Co and Vice President of Vanlead Rubber & Tire Research Institute, Dr Xiaoguang Yang is leveraging current research to enhance corporate competitiveness. He has several years of professional research and technical management experience in tyre and vehicle performance testing, analysis, modelling and simulation. In this interview to Tyre Asia, Dr Xiaoguang, who has a PhD from Birmingham University, speaks on a wide range of tyre-related questions, including development of tyres as sensors. Excerpts
Why is that the rolling deformation of tyre is a direct result of tyre-road interactions?
Tyres are serving as an important part of various transportation systems, such as automobile, aircraft and light rail transit, etc. They are subjected to different kind of forces generated from its deformation during these services.
Apart from the inflation deformation, tyre rolling deformation is a direct result of tyre-road interactions, which is also usually varying significantly with rolling tyre states. Because when tyres provide functions serving vehicle performance such as supporting automobile weight, cornering, traction and braking, etc. the tyre-road interactions states (such as contact patch shape, contact stress and strain) also change which directly lead to the tyre rolling deformation change.
It is observed that measuring such deformation will provide useful information for tyre designers. How do you measure these parameters?
Currently, there exists different methods to collect tyre rolling deformation information, while the core behind these methods is sensor technology. Engineers and researchers around the world are using accelerometer, strain sensor, optical sensor, PVDF sensor, SAW sensor, ultrasonic sensor, etc. to measure tyre rolling deformation. Although these measured results could be acceleration, strain or deformation, they are all related to tyre rolling deformation. In my research work, strain sensors are used to measure tyre deformation effect with a wireless data acquisition system.
Researchers have used multi-laser sensor systems to make rolling tyre deformation measurements. It also helps in measuring tyre inner contour changes due to the inflation and wheel load. How can the laser systems be incorporated in tyres?
Multi-laser sensor systems used for rolling tyre deformation measurement is an innovative approach to provide high precision data and non-contact measurement. Dr. Tuononen, A. and Xiong, Y. from Aalto University, Finland, had carried out a series of pioneering work on tyre using multi-laser sensor system. The multi-laser sensor systems usually are incorporated on the rim, while the rim need further modified in order to house the laser system. A slip ring is used to transfer power and signals from a rolling tyre to an on-board data acquisition system. Therefore, currently multi-laser sensor systems are suitable for research in laboratory rather than application. In future, with the development of small and lightweight systems, there is potential to incorporate them on the rim without destroying rim structure.
How far has the tyre industry progressed in developing intelligent tyres? Do you think tyres will soon become virtual sensors and enhance the safety of passengers and vehicles?
It is difficult to give an accurate prediction on intelligent tyre technology development. However, one thing is confirmed that the development of intelligent tyre technology is speeding up nowadays and faster than in the past two decades and it is becoming more interesting. The intelligent tyre with basic concept assembling TPMS and RFID has been available around the world. The intelligent tyre with advanced sensors such as for rolling deformation measurement will not be far, especially with the development of Artificial Intelligence, BIG data, etc. This collected information could be very useful for vehicle and transportation system from safety to management.
On the other hand, the breakthrough may be created by car makers who are also working on intelligent tyre technology such as Audi. I think tyres will soon become virtual sensors. In future, on the panel of a car, more and more tyre-related information will be displayed. Furthermore, the status estimation or decision made based on tyre information would greatly improve vehicle dynamics control, such as ABS, TCS, ESP, etc. Intelligent tyre technology will make driving much safer.
Is it possible to retread such intelligent tyres? How would such system draw electric power and what are the current technology trends in this regard?
Apart from RFID tyres, most currently developed intelligent tyres are not suitable for retreading due to the hazard of high temperature curing process on sensor system. Generally, the intelligent tyre system need power supply units which may not only increase the system volume and weight, but also has negative influence on tyre sensor system stability, such as the limitation of power storage. However, several technologies without power supply unit have emerged such as RFID and SAW-based TPMS. With regard to current technology trend, the electric power of intelligent tyres could be progressed in two directions: one is passive wireless sensing, the other is self-powering such as energy harvesting from tyre vibration or deformation.