How Six-Axis Sensor ICs Work

Last Update Time: 2023-03-11 14:11:49

    Six-axis inertial sensor ICs, or sensors, are IC chips that measure a host of parameters related to motion. These sensors provide an array of outputs for an array of parameters, such as acceleration or velocity, position or displacement, and rotation or tilt, along the three-dimensional space. They are also referred to as 6 degrees-of-freedom (DOF) sensors since they measure six parameters in total; each representing X, Y, and Z axes. Variations in pressure, humidity and magnetic fields all affect the linear and angular motion of a device.

    Six-axis inertial sensor ICs are highly integrated chips that measure acceleration, angular rate and magnetic field along six axes. They normally incorporate three key components; an accelerometer, a gyroscope, and a magnetometer. A variety of semiconductor materials, such as MEMS (Piezoelectric and Microelectromechanical Systems), CMOS (Complementary metal-oxide-semiconductor) and hall-effect are used in the fabrication of inertial sensors. With these components, the IC is able to accurately measure, store and analyze the three-dimensional data regarding movement of a device in real time, which is essential in automated navigation, augmented reality and surveillance camera activities.

    A gyroscope measures the angular velocity in the three-dimensional space using dynamic or static elements. Dynamic elements are based on the Sagnac effect, whereas static elements are based on the Coriolis effect. The Sagnac effect is produced when light is split and directed around a closed loop and then recombined; the combined light wave experiences a phase shift that is proportional to angular rotation. In the Coriolis method, two transducer coils are mounted orthogonally in a proof mass. If a coil is oriented perpendicular to the body, its inductance is varied by the Coriolis force, which is proportional to the angular velocity.

    An accelerometer, on the other hand, measures the acceleration of a device along the three-dimensional space by changing the capacitance between two plates. This change in capacitance is used to measure the acceleration of the device in the three-dimensional plane. As the device moves, a change in acceleration will cause electrostatic force on the plates, which is detected and translated into an output signal.

    The magnetometer, much like the accelerometer, measures linear acceleration and angular velocity of a device but through electromagnetic forces instead of electrostatic forces. As the device moves in a three-dimensional plane, various magnetic fields are generated, these fields are then detected and the output is translated into a measurable voltage. This voltage is used to calculate the linear and angular velocity of the device.

    With the combination of these three components, the inertial sensor IC is able to measure and keep track of motion of a device in a three-dimensional plane. By incorporating multiple sensors in one IC, manufacturers are able to provide more accurate measurement systems in a much smaller package size. These ICs are also used in image stabilization systems and auto-pilot systems, giving devices the capability of autonomous navigation. With the help of these ICs, devices can accurately measure the motion of a device and navigate the environment.