Improving the response of wheel speed sensors by using robust and optimal signal processing techniques

Abstract

Among the complete family of sensors for automotive safety, consumer and industrial application, speed sensors stand out as one of the most important. Actually, speed sensors have the diversity to be used in a broad range of applications. In today's automotive industry, such sensors are used in the antilock braking system, the traction control system and the electronic stability program. Also, typical applications are cam and crank shaft position/speed and wheel and turbo shaft speed measurement. In addition, they are used to control a variety of functions, including fuel injection, ignition timing in engines, and so on. However, some types of speed sensors cannot respond to very low speeds for different reasons. What is more, the main reason why such sensors are not good at detecting very low speeds is that they are more susceptible to noise when the speed of the target is low. In short, they suffer from noise and generally only work at medium to high speeds. This is one of the drawbacks of the inductive (magnetic reluctance) speed sensors and is the case under study. Furthermore, there are other speed sensors like the differential Hall Effect sensors that are relatively immune to interference and noise, but they cannot detect static fields. This limits their operations to speeds which give a switching frequency greater than a minimum operating frequency. In short, this research is focused on improving the performance of a variable reluctance speed sensor placed in a car under performance tests by using a recursive least-squares (RLS) lattice algorithm. Such an algorithm is situated in an adaptive noise canceller and carries out an optimal estimation of the relevant signal coming from the sensor, which is buried in a broad-band noise background where we have little knowledge of the noise characteristics. The experimental results are satisfactory and show a significant improvement in the signal-to-noise ratio at the system output.

Robust control of a buck-boost DC-DC switching regulator for the electronic systems of next-generation cars

“…It is known that the introduction of many new electronic developments in today's cars, such as electric power steering, braking, suspension, accelerator, electronically actuated engine valves, and sensors and actuators, see [9][10][11][12][13][14][15][16][17][18][19], among other references, demands that the electronic engineers build highly efficient power supplies. This is why, in this project, an H ∞ controller was used to design a robust and optimal buck-boost dc-dc switching regulator to deal with the inevitable disturbances that corrupt the satisfactory performance of both the electrical and electromechanical systems used in cars.…”

Application of Wavelet Transform in Vehicle Wheel Speed Signal Denoising

“…There are kinds of wheel speed sensors, such as variable reluctance sensors, Wiegand effect sensors, Hall effect sensors and so on [5]. At most cases variable reluctance sensors are used.…”