The optimal center of gravity position is selected by measuring the inertia of the smart car, and the smart car can be accurately positioned in a running state such as a straight line, a curve, a ramp, and a drift; the acceleration sensor can predict the path in advance and determine when the braking effect is optimal. And it is a good solution to the balance and direction identification of the upright walking car model.
Therefore, a design based on three-axis acceleration sensor in smart car and path recognition is proposed. The design uses the three-axis accelerometer MMA7260Q to measure the acceleration signal of the smart car in motion. The embedded single chip MC9S12XSl28B is used as the core controller to sample the acceleration signal, A/D conversion, and then store the feature data in the EEPROM. The problem of smart car motion path analysis is well solved. The acceleration of the car is obtained in real time, so that the running state of the car is more comprehensively obtained, which provides the possibility of controlling the fluency and better road condition recognition.
In the car model that walks upright, the same principle is applied, and the best center of gravity is selected, which can well solve the balance and direction recognition of the upright walking car model, thereby speeding up the driving speed of the car model.
Market research firm IHSiSuppli pointed out that thanks to the rapid adoption of automotive safety regulations and the application of automotive safety systems in recent years, the market for composite MEMS inertial sensors for automotive applications is expected to reach US$163 million in 2013, a substantial increase of 77%.
IHS said that the use of these types of sensors in cars is rapidly increasing as more and more cars are introduced into safety systems. Last year, this type of sensor market grew by about 338%, reaching a market size of $92 million, a significant increase from $10 million in 2011.
The hybrid inertial sensor is a multi-sensor component that integrates an accelerometer and a gyroscope in a single package. It provides inertial input to the electronic stability control system (ESC) in the car to avoid or reduce slippage.
“In North America, Europe, and other places where regulations are ripe, such as Australia, Japan, Canada, and South Korea, cars are mandated to adopt ESC systems,” said Richard Dixon, principal analyst for MEMS and sensors at IHS, however, “in some untapped areas. There are still huge business opportunities, such as China providing a larger market, which will obviously affect the penetration rate of ESC in the world. However, from another perspective, it will also be a composite sensor belt for the whole vehicle. Great growth drivers and kinetic energy."
VTI's tilt sensor is composed of high quality silicon capacitive sensor components and interface electronics and is packaged in a specific application package. The components of the silicon capacitance tilt sensor are made of monocrystalline silicon and glass. This design ensures unprecedented reliability and excellent stability with respect to time and temperature reliability. Usually a component can withstand an acceleration of more than 40,000 g (1 g = acceleration of the Earth's gravity).
There is no plastic deformation and hysteresis in single crystal silicon, which is either successfully fabricated or completely destroyed. The cantilevered dual-capacitance sensing element features overload protection that measures acceleration in both directions.
The core of the tilt sensor is a symmetric capacitive block of micromechanical acceleration sensor elements consisting of three silicon wafers separated from each other by a thin glass film. The intermediate silicon wafer is a cantilever multi-ray structure, and the large mass above it, the capacitance and the spring constant can be independently obtained to obtain the best results. This is why it is a good measurement result in the low g range. The force of gravity and acceleration acting on the silicon wafer causes the single crystal silicon beam to oscillate and oscillate. This deviation can be measured by the change in the distance between the capacitances of the electrodes of the two metal films. Micromechanical sheets enable relatively large changes in capacitance and capacitance to be detected.