Application of New Pressure Sensors in Automobiles
Automotive designers continue to demand devices that offer higher performance and more flexibility than traditional position sensing technologies. And these devices have to be versatile and adapt to a wide variety of applications. The
This requirement requires the integration of traditional contact-type sensor technology and various optimal design elements included in non-contact sensor technology within the device. The
As today's cars use more and more electronic and control systems, engineers face the increasing challenges of integrating these electronic devices into automobiles.
This is especially true for those sensors and other feedback (parameters) circuits that are used to ensure the safety of the car, reduce fuel consumption, and reduce radiation. SHELOK Air Pressure SensorTo be consistent with processors that handle higher speeds and I/O functions, electronic system designers are always faced with various challenges in improving system resolution and signal quality. For any sensing technology used in today's automotive environment, mechanical flexibility, environmental stability, and signal integrity are key design features.
The One of the requirements for electronic devices is the range of operating temperatures they can withstand. Temperatures range from a cold ambient temperature of -40 degrees Celsius to over +150 degrees Celsius in the engine compartment. Sensors and related electronics face the extreme temperatures that current materials can withstand. Further applications, such as variable turbochargers, will continue to push this extreme temperature, which may exceed +180 degrees. This requires sensor designers to develop materials and packages that meet these needs. At the same time, the sensors must be able to accept the various mechanical configurations required by the overall system. Traditional sensing devices such as potentiometers and Hall effect devices (technologies) can be packaged in either a linear or a ring type. Both of the above technologies have their own advantages - lower potentiometer cost, mature technology, flexible mechanical structure, low wear of Hall effect devices, and good signal quality - which one to use depends on the application requirements of the system To be determined. More advanced technologies such as inductive sensors use the advantages of the two sensors described above to achieve a more robust sensing system. Potentiometer technology has high design flexibility for linear or ring applications. Based on the design characteristics of the potentiometer, it provides an output signal proportional to the input voltage. However, this technique is somewhat limited by the nature of its analog output signal. Although this signal can be converted into a digital format, this conversion requires additional electronics and increases the cost of the sensor. Moreover, the converted signal is not yet a true high-resolution digital format. With more and more high-speed networks and communications
The bus is applied to the car and the need to arrange an AD converter for each potentiometer can be a disadvantage. Potentiometers are also a type of contact sensing technology and are prone to wear due to long-term operation and vibration. When the potentiometer wear becomes very obvious, it will cause the signal to contain excessive noise. This will become a question in the direct feedback control loop
question. The Hall-effect sensors typically produce an analog signal. The device's communication with the automotive system is implemented by an ASIC that also converts the analog signal directly into a digital signal. Because Hall technology measures changes in Gaussian magnetic flux, very sophisticated support systems are needed to maintain its integrity. This limits the mechanical packaging flexibility of these devices to some extent. This kind of bearing system also increases the cost of the pressure sensor to some extent. The advantage is that Hall-effect sensors are non-contact and therefore do not lose performance due to wear like potentiometers. In general, such sensors have a relatively short moving distance in order to control the Gaussian magnetic field that affects Hall effect sensors. Hall effect sensors are typically designed to be less than 180 degrees of rotation or less than 25 millimeters of linear motion.
The Recent advances in the development of new inductive sensing technologies have utilized the advantages of both potentiometer and Hall effect technologies. The device contains a non-contact sensing system consisting of two printed circuit boards, the core of which is signal generation and sensing. The device, called Autopad, creates inductive coupling between the two boards and is measured and converted by the on-board ASIC. Unlike Hall sensors, the Autopad sensor allows misalignments in the X, Y, and Z axes, so a rigid carrier system may not be required. In addition, the ASIC makes it a true digital sensor capable of producing 12-bit PWM signals that can communicate directly with high-speed controllers. This signal can also be converted back to analog format if needed. OPTEK's Autopad can also be implemented using a variety of physical structures, including rotating and linear structures. The rotary design can be used for systems with angular misalignment of up to 360 degrees. Linear sensors allow for misalignments of 20 to 200 millimeters or more. The
As the automotive industry develops, design engineers continue to demand devices with higher performance and flexibility. Although traditional sensing technology has its advantages, the development of inductive sensing technology provides a solution for solving various technical challenges and meeting the needs of the current demanding automotive electronics. The design flexibility of this sensing technology makes it a reliable and more cost-effective solution for many automotive applications.