Vehicle Sensors

Many Vehicle Sensors, sensor fault judgment, should not only consider the the sensor itself, but should consider the failure of the entire circuit. Therefore, in the search failure, in addition to check sensor, but also check the wiring harness, connectors and related circuit between the sensor and the electronic control unit.

Basic Function:

The sensor refers to the physical experience requirements, and according to certain rules to convert the input signal of the device or devices available. Simply, sensor is the electricity conversion device. The sensor is usually composed of non electric sensitive element, conversion element and measurement circuit composed of three parts. 1), the sensitive element refers to the direct feeling (or response) by measuring part will be measured by the sensing element and the measured is converted into electricity or other quantity relationship. 2), the non electricity converting element converts electrical parameters. 3), the measuring circuit is the role of the input electrical parameters after conversion element processing to convert the voltage, current or power frequency can be measured, for display, record, control and processing part.

Category:

The air flow sensor is the inhaled air is converted into electrical signals sent to the electronic control unit (ECU), as one of the basic signal injection. According to measuring principle is different, can be divided into rotary vane type air flow sensor, Carmen vortex type air flow sensor, hot wire air flow sensor and the hot film air flow sensor four the first two types. As the volume flow type, which is the quality of flow type. Using hot wire air flow sensor and the hot film air flow sensor two. The intake pressure sensor can measure the absolute pressure in the intake manifold of the engine according to the load condition, and converted into electrical signals and speed signals together into the computer, as determines the injector fuel injection quantity basis. Is the widely used semiconductor varistor type air pressure sensor. The solar term door position sensor mounted on the day The valve, used to detect solar term door opening. It through the linkage lever mechanism and the solar term door, which reflect the different engine working conditions. The sensor can be put in different conditions after the input detection engine electronic control unit (ECU), so as to control the fuel injection quantity. It has three different types: switch contact type solar term door position sensor linear, variable resistance type solar term door position sensor, integrated solar term door position sensor, crankshaft position sensor crankshaft position sensor crankshaft position sensor or crank angle sensor, the sensor is the most important in computer controlled ignition system, its function is to detect the TDC signals, crank angle signals and engine speed signal, and input it the computer so that the computer can be in the firing order of the cylinder from the best ignition time instruction. Crankshaft position sensor has three types: electromagnetic pulse Crankshaft position sensor, crankshaft position sensor Holzer effect, photoelectric effect type crankshaft position sensor. The crankshaft position sensor of different types, the control method and the control precision is different. The crankshaft position sensor is installed on the crankshaft pulley or sprocket side, some mounted on the front of the cam shaft, there are installed in the distributor. The knock sensor installation in the engine block, the monitoring of engine knock. The resonance and non resonance type two categories.

Static performance parameters:

The static performance parameters of the sensor sensitivity refers to the ratio of the sensor output y and input X of the steady state, and the increment of input or output x y increment ratio, denoted by K k=dy/dx, the minimum resolution of change of the quantity being measured in the measurement of force sensor can be detected within the prescribed scope of the called the resolution. 3 the measuring range and the range of the allowable error limit, the lower limit of the measured value to the upper bound of the range between the called measurement range. The linearity (nonlinear error) under specified conditions, the calibration curve fitting and the percentage of the maximum deviation between the line sensor and full-scale output value is called linearity or the nonlinear error. Hysteresis refers to under the same operating conditions, the extent of the inconsistency and anti stroke characteristic positive stroke characteristics of sensor. The repeatability reproducibility refers to the same working conditions, The inconsistency of the input in the same direction in the whole measuring range change continuously in multiple characteristic curve. The income of zero drift and temperature drift of sensor without input or to another value, at regular intervals, the input value of percentage deviation from the maximum deviation of the original value and the full range of zero drift. When the temperature rise of 1 degrees Celsius, the maximum deviation of the sensor output value and the full range of percentage, called the temperature drift.