Meaning the performance indicators tilt sensor
As the angle sensor measuring the angle of the object relative to sea level measuring device, continuously improve the accuracy of the product, a wide range of applications and professional gradually, manufacturers very much. However, the market most of the tilt sensor accuracy of the description, is ambiguous or there is a certain bias.
Generally speaking, in accordance with the Metrology Law and relevant national / international standards, there is a description of the overall accuracy and certainty of description, these descriptions are universal, whether the field is suitable for tilt sensors, is questionable. Everywhere we can get a variety of different tilt sensor or accuracy of the description of the product suppliers in the market, most of the non-linear inclination sensor as the measurement accuracy of the sensor, this is done, there are some deviations.
First, we need to analyze the factors affecting the measurement accuracy of the tilt sensor which then discuss how to determine the accuracy of the definition of a tilt sensor to tilt sensor acceleration principle as an example. It is the gravity acceleration component data is converted into an angle of the acceleration sensor sensitive axis, i.e., the tilt value and an acceleration value into a sinusoidal relationship. This principle in many literature and product descriptions given full instructions.
Accuracy of measurement of the tilt sensor is closely related to the following specifications:
Sensitivity error - depending on characteristics of the core itself sensitive devices, but is associated with the frequency response, also referred to as amplitude-frequency characteristic. After the actual test, the impact on the sensitivity of small, negligible.
Zero offset - dependent on the core itself characteristic sensitive devices, sensor means in the case where no angular input (e.g. absolute level), the sensor measuring the output is not zero, the actual output value is the zero offset angle. Whether this indicator sensor can be set to zero with nothing to do
nonlinear - it can be corrected by follow-up, depending on how many calibration points. The more calibration points, the better the nonlinearity.
Is coupled to an error in the sensor output signal generated when the sensor means when the acceleration is applied in a certain direction or perpendicular to the sensitive axis inclined at an angle - axis error. As the measurement range of ± 30 ° uniaxial (assuming the direction of tilt measurement X direction) tilt sensor, a tilt angle of 10 ° at the inclined space occurs perpendicular to the X direction (at this time is actually measured in the X direction remains unchanged , such as + 8.505 °), the output signal of the sensor because of the inclination of 10 ° is generated an additional error which is called axis error. This additional error due to different of the product. When the tilt sensor is the transverse axis error 3% FS, generates an additional error of 3% × 30 ° = 0.9 °, the actual angle sensor output from a simple estimate of 9.405 ° (= 8.505 ° + 0.9 °). In this case, even if the nonlinear error of the tilt sensor reaches 0.001 °, relative to axis error terms, the non-linear error can be ignored, that is to say, as the measurement accuracy of the tilt sensor, including the error can not calculate the horizontal axis, otherwise it will cause a lot of measurement errors.
