Yang Y.,Tsinghua University |
Yang Y.,Shenzhen Lionax Automotive Information Technology Inc |
Min Y.,Shenzhen Lionax Automotive Information Technology Inc |
Shen Q.,Shenzhen Lionax Automotive Information Technology Inc |
And 3 more authors.
Chinese Journal of Sensors and Actuators | Year: 2010
Tire Pressure Monitoring System (TPMS) has become an important automotive electronic safety device with extensive application for vehicles, but traditional TPMS is typically internal device. The sensor unit is placed inside of tires, which is hard to maintain and install. The metal wires nested inside of tire have strong shielding effect for sensor and wireless transmission, and the signal is largely attenuated because of that. In order to guarantee that the signal can reach the receiver placed on the driving panel, the transmission power must be increased thus seriously decrease the battery lifetime. To solve all these technical difficulties, a new type of external TPMS sensing device with direct pressure measurement has been developed. The key component of new TPMS is a MCU from Infineon SP30 with build-in MEMS pressure sensor. The tire pressure can be measured directly from valve stem connection and pressure data is transmitted wirelessly to the monitor on the driving panel. It avoids the signal shielding effect, extends the battery life and reduces maintenance cost. The specific circuit design, software and protocol for communication have been given in this paper. The system is demonstrated with identified characteristics such as very stable wireless transmission, good performance for anti-interference, accurate recognition for tire position , fast response time for pressure change, easy installation and maintenance, and very flexible for tire configuration, etc. The new TPMS device has big prospect for real application.
Yang Y.,Tsinghua University |
Yang Y.,Shenzhen Lionax Automotive Information Technology Inc. |
Shen Q.,Shenzhen Lionax Automotive Information Technology Inc. |
Min Y.,Shenzhen Lionax Automotive Information Technology Inc. |
And 5 more authors.
Qinghua Daxue Xuebao/Journal of Tsinghua University | Year: 2011
The main technical difficulties in tire pressure monitoring systems (TPMS) are the reliability and stability of the wireless communications and how to prolong the battery lifetime for the pressure sensor transmissions. These technical difficulties are addressed with low power transmission and receiving circuits. The transmission and radiation resistance characteristics of the receiving antenna, the loss resistance, and the inductance were analyzed with network matching to improve the transmitting efficiency of the low power circuits. The influence on the receiving signal sensitivity and performance related to multipath fading and the Doppler shift caused by the high speed wheel movement were analyzed with a new communication algorithm developed to optimize the system. An effective and reliable antenna scheme was developed with an improved communications protocol. Its overall performance for the static, dynamic, and actual loading effects on vehicles is satisfactory and exceeds the requirements for the international TPMS standard.