|
Tire Pressure Monitoring System(TPMS) is a very important part of Automobile Security System, and the systemic stability and reliability has a straight bearing on a driver’s personnel safety. Remote Tire Pressure Monitoring(RTPM), the collection of the crucial data by it, such as tire temperature and pressure, etc., especially has a full impact on the next process of the system. Because the module is in a very vile environment, above all, making sure all parts of the apparatus could work up to snuff and have much higher stability and reliability. For instance, the pressure sensor for TPMS made by Motorola is chosen to measure pressure. Thus, it not only satisfies the environmental requirements but also supplies many CMOS chips with different measurement ranges aimed at different vehicle model for a choice; and their operation is very convenient, and their capability is very reliable; the battery in use is Li-SOCl2, and this type one is a special type Li-battery, not only does it have so many characteristics, such as much great capacity, very little local action and very smooth discharge curve, and so on, but also its low-temperature and high-temperature characteristics are not assimilated with common Li-battery’s, so it is fit for being lastingly used in a very vile environment very much; otherwise, all, included the acceleration sensor used to awake the module, wireless transmit-receive module used for wireless communication and MSP430 MCU made by Texas Instruments, Inc. in special use, have very strong capability to accommodate the environment and much higher stability and reliability. Otherwise, in order to make sure the system can work lastingly, and economize energy and cut down cost to the utmost extent, the systemic low power consumption characteristic may not be ignored. Therefore, no matter what the Hardware Design or the Software Design, at the same time that make sure the systemic stability and reliability, pays attention to the systemic power consumption in particular, the static power consumption of all parts of the apparatus is on microampere level, except that the power consumption of wireless transmit-receive module in work is a little great(milliampere level), others are still on microampere level, especially MSP430 MCU. It has many peripheral equipments in the chip being supplied for the user. However, the power consumption is hardly increased, especially when many programme sentences are appended to control the power consumption, users may choose the lowest current, only 0.1μA, according to the requirement; this is indeed less than the current of the local action of a battery. Therefore, it is fit for the exploitation and use of the low power consumption product in particular.
|