Tilt sensor is an important tool for measuring inclination Angle, which is widely used in industry and military, such as the Angle measurement of missile launching guide rail, the attitude measurement of ship navigation, etc.
In reality, the measurement of the Angle of the inclinometer sensor is focused on the accuracy of the measurement, so it becomes particularly important to improve the measurement accuracy. The working environment temperature of the tilt sensor changes greatly, and the measurement error caused by the working temperature accounts for a large proportion of the overall error, so this paper mainly analyzes and tests the temperature characteristics of the sensor.
It is found that the accelerometer, the analog-to-digital converter and the whole sensor housing have a serious influence on the measurement accuracy of the sensor. On this basis, we propose a method combining least square method and piecewise linearization for temperature compensation, which greatly improves the measurement accuracy.

1. Temperature characteristics of the sensor

The overall measurement process of the inclinometer sensor is the required data measured by the main measurement unit accelerometer, sent to the analog-to-digital (A/D) converter for processing, and then sent to the MCU together with the temperature sensor data for processing, and finally displayed by the communication unit. Accelerometer is the main tool to calculate the Angle and the basis of the realization of the tilt sensor. Second A/D converter
Related to the overall resolution and accuracy, they are greatly affected by temperature, is the main consideration.

1.1 Analysis from the overall perspective

When the tilt sensor is actually measured, it is to put the whole on a platform for Angle measurement, so the consistency of the inclinometer sensor base and the placement platform has a great impact on the overall measurement. For cost considerations, the base of the inclinometer sensor is generally made of aluminum alloy, and this material will expand and shrink with the change of external temperature, which directly affects the measurement of Angle.

1.2 Analysis from the main measurement unit

Accelerometer is the main measuring tool of sensor. It has the advantages of high precision, small size and wide operating temperature range. Because the working environment of its application is generally harsh, the temperature has become the main factor restricting the measurement accuracy. The influence of temperature on the accelerometer is that the change of temperature will affect the deformation of the accelerometer and the change of physical parameters, such as the torque length, magnetic induction intensity, resistivity, etc.
1.3 Analysis from the perspective of data processing
The A/D converter we choose is model CS5532, which converts the analog voltage value collected by the accelerometer into a digital signal for data processing by the MCU, and meets the basic technical requirements of the tilt sensor design. Assuming the accuracy of the A/D converter is n, the output voltage of the accelerometer is Vout, and the reference voltage of A/D is Vref, then there is an output value:,,,,,,