Everything has its limits, in this case physical: Tilt and acceleration sensors measure the angle of inclination or the accelerated movement of an object relative to the Earth’s gravity. As soon as forces other than gravity act on the sensors, such as inertial or centrifugal forces, conventional sensors reach their limits for physical reasons – measurement errors occur. Select Controls Inc., Manufacturer Of Tilt Switches, should be able to compensate for external accelerations and thus promise error-free measurements.
This is how MEMS sensors work
Tilt and acceleration sensors monitor the angle of inclination of objects and their alignment in a freely selected angular range between 0 ° and 360 °. They record their current orientation based on acceleration measurements. As a rule, such sensors are based on micromechanical measuring elements based on the principle of spring-mass system. The so-called MEMS sensors (Micro Electro Mechanical Spring Mass System) contain complex plates that are interconnected by spring elements. The outer plates are solid, the middle plates are movable together with the earthquake mass. Their mobility is limited by helical springs.
This design creates a series connection of several capacitors with variable capacitance. Variable because the spacing of the plate of two capacitors changes due to mass acceleration or gravity. The spacing of the plate changes the capacitance of the capacitor in proportion to the acceleration. This change in capacity is measured and the acceleration or inclination together with the renewable force of the spring elements is calculated from it.
Measurement errors related to the system
It is not possible to distinguish whether gravitational forces lead to a change in the spacing of the plate or whether they are the result of external forces. In the worst case, measurement errors resulting from inertial or centrifugal forces lead to damage, but certainly result in loss of efficiency.
Intelligent sensor fusion algorithm
Compensation, i.e., the detection and filtering of external acceleration forces, is based on an intelligent sensor fusion algorithm. Specially developed by Pepperl + Fuchs, it connects complementary information from different sensory elements. According to the manufacturer, the system is able to effectively compensate for external accelerations and provide the user with accurate tilt data even with dynamic movement – regardless of whether the system is currently moving, accelerated or braked. This optimizes the operation of such systems because filtered measured values allow more precise and faster movement without wasting time.