July 12, 2023
Accelerometers are devices that measure acceleration in units of g on one, two, or three planes. The most commonly used accelerometer is the 3-axis accelerometer, which consists of three accelerometers, each measuring acceleration in a different direction in the X, Y, and Z planes. When the acceleration in any plane acts in the opposite direction to that which the sensor is pointing, the accelerometer measures the acceleration in negative values. Otherwise, acceleration is measured as a positive value. If the accelerometer is not affected by any external acceleration, the device will only measure the acceleration with respect to the Earth, i.e., gravity.
The measurement of acceleration is essential in an inertial navigation system, and the accelerometer is the device used to measure acceleration. Acceleration is a physical quantity that reflects the speed change state of an object in the process of movement. However, acceleration cannot be measured directly and is usually measured indirectly by something that can be measured directly, such as time or displacement. Current accelerometers use indirect measurement and force balance to obtain acceleration.
The output of the acceleration sensor reflects the net force of the sensitive balance in the sensor in the whole space, mainly including inertial force and gravity. When the object moves in space, the sensor can obtain the acceleration of the object in real-time. The instantaneous velocity of the object can be obtained by integrating the acceleration once, and the relative position of the object can be obtained by integrating the velocity once. Using these three parameters, the motion trajectory of the object can be described.
The Quartz flexible accelerometer is a force feedback pendulum accelerometer and is developed on the basis of the liquid floating pendulum accelerometer. The main difference between the two is that the detection quality of the quartz flexible accelerometer is not floating, but elastically connected to the flexible beam support, introducing elastic moment. Therefore, this kind of accelerometer has higher accuracy, strong anti-interference ability, large measuring range, and strong overload capacity.
The quartz flexible accelerometer has been widely used in the measurement of various linear acceleration and vibration acceleration, as well as the measurement of velocity, distance, angular velocity, angular displacement and other parameters. It has been successfully used in military and civilian fields such as satellite microgravity measurement systems, high-precision inertial navigation systems, rock and soil-based borehole measurement and oil drilling, continuous inclinometer system, carrier rocket, ballistic missile, and spacecraft. The performance of the accelerometer is directly affected by the performance of the flexible material used as the pendulum, and quartz has high anti-fatigue strength and small hysteresis, making it very suitable for use as the pendulum of the accelerometer. The quartz flexible accelerometer has replaced the liquid floating accelerometer and become an indispensable key device in the inertial navigation and guidance system.
