Accelerometers are getting more and more attention, not only because it is a sensor to measure the acceleration of objects with its unique physical and mechanical principles, but also because with the development of intelligence, accelerometers , which have been further improved from the material, structural design and accuracy are widely used in the fields we are familiar with.
Quartz flexible accelerometer is one of the many accelerometers with simple structure, performance, volume and price advantages. It is a sensor that can feel acceleration and convert it into an available output signal, which is completely dependent on its own physical and mechanical properties, independent of external electricity, light and magnetism. The inertial navigation system composed of it and gyroscope has the advantages of autonomy, concealment, real-time and all-weather. Therefore, it has been widely used in the navigation, positioning and stability control of various carriers.
Material property characteristics
The performance of flexible material directly affects the performance of accelerometer. The materials that can be used as flexible pendulum are mainly metal and quartz. The traditional liquid floating pendulum accelerometer pendulum uses metal materials, and the thermal expansion coefficient of quartz is much smaller, and the heat resistance is strong, and the material performance is better than that of metal. ER-QA-03A produced by quartz material can reach 10-50μg in bias stability. The scale factor repeatability is 15-50ppm, and the Class II non-linearity repeatability can reach 10-30μg/g2, which has become an indispensable key device in inertial navigation and guidance systems.
Structural design characteristic
The quartz flexible pendulum accelerometer is elastomically connected to the flexible beam support and introduces the elastic torque, so the accelerometer has higher accuracy, strong anti-interference ability, large measuring range and strong overload ability. For example, the measurement range of ER-QA-03B is ±70g, the bias stability is 10-30μg, and the Class II non-linearity repeatability is10-30μg/g2. It can provide accurate data reference for the measurement of various linear acceleration and vibration acceleration and the measurement of speed, distance, angular velocity, angular displacement and other parameters.
Accelerometers are often used in agile inertial navigation, and the measurement devices are installed on the subjects that need navigation information such as drones, ships, aircraft and vehicles. Therefore, in practical application, the accelerometer may be in vibration, shock, temperature upheaval and other harsh environmental conditions for a long time, which has a great impact on its measurement accuracy, stability and life. The inertial navigation has strict requirements on the performance of the quartz flexible accelerometer. If it has high accuracy and good stability, it can extend the working cycle of the whole system and improve the working efficiency. For the special environmental conditions mentioned above, such as the complex situation of vibration impact environment, including the unknown direction of external force, duration and strength of the different will cause damage to the component and shell to a certain extent, but also in the case of the accelerometer value error, the quartz accelerometer ER-QA-02A designed for this has the characteristics of anti-vibration. It also maintains 100 (3 to 7 days)μg on the bias stability , the scale factor stability is less than 100 (3 to 7 days)ppm, and the operating temperature can reach -45 to +150℃. Therefore, the appropriate accelerometer can be selected according to the characteristics of the application field of the relevant product.
In addition, we can see the use of accelerometers in military and civilian fields such as satellite microgravity measurement systems, high-precision inertial navigation systems, rock and soil drilling measurements, oil-sucking drilling, continuous inclinometer systems, launch vehicles, ballistic missiles, spacecraft, and so on.