Sensata Designs Reliable Tire Pressure Monitoring System With NI AWR Software
Sensata Technologies, formerly known as Texas Instruments Sensors and Controls, is a leading supplier of controls and sensor systems. Sensata’s industry-leading product lines include: automotive sensors, motor protectors, circuit breakers, HVAC pressure sensors, thermostats, and switches.
The Design Challenge
As safety demands escalate for the global automobile market, automobile manufacturers are looking to keep pace using more intelligent monitoring systems to enhance driver safety. Emphasis is being put on increasing the reliability and sophistication of these systems, including tire pressure monitoring systems (TPMS), which have been proven to be effective in reducing single car accidents caused by insufficient tire pressure. Working to fulfill this need, Sensata has developed a TPMS system that leverages RF technology.
The system comprises four sensors, one fitted on each wheel of a car, which provide the ability to measure pressure and relay it to a receiver. This receiver communicates with the car dashboard electronics to warn the driver of any decrease in tire pressure or sound an alarm in case of a puncture or rapid decrease in tire pressure. Because the TPMS sensors are fully contained units that include power, optimizing the efficiency, cost, weight, and size of the antenna and RF section are crucial design requirements. Additionally, because these systems must be able to survive and operate reliably in extreme temperature, weather, and physical shock/vibration environments, they must be very robust.
Design optimization is a common issue in RF circuit analysis and relies heavily on network/impedance matching. In many applications there are restrictions not only on RF parameters, but also on size, shielding, and more. With the large number of device and system constraints, as well as the parasitics involved, it can be very time consuming to find the most optimum RF design.
Sensata chose NI AWR Design Environment, specifically Microwave Office circuit design software, inclusive of AXIEM 3D planar electromagnetic (EM) simulator and Analyst™ 3D finite element method (FEM) simulator, to simplify and enhance the demanding design process for its RF TPMS system.
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TPMS Design Presentation