Sensing Solutions Contributing to Society
Sensing means to understand various information by measuring and quantifying it using a sensing device. There are three main fields in our sensing solution technologies: position sensing to understand position, vital sensing to understand the activities of people, and motion sensing to understand movements. Here we describe our sensing solution technologies.
Position Sensing for Understanding Position
Position sensing helps us understand where a person or object is now. The Global Navigation Satellite System (GNSS) device is a leading key device in position sensing. GNSS, which allows us to understand the current position of a person or object on the earth with radio waves from satellites, was originally created for military purposes. However, it is now installed in car navigation systems, aircraft, smartphones, watches, cameras and various other products.
Our innovative low-power GNSS devices are both small and highly accurate. These devices are also compatible with "Michibiki" Quasi-Zenith Satellite System produced in Japan to boast a reception sensitivity. We are using these technologies to produce products include our original analog watch called Trume that always displays the correct time by identifying the time zone of its current position using just GNSS satellite radio waves.
Vital Sensing for Understanding Activities
Vital sensing is a solution to measure vital signs with a sensing device. Our original pulse measurement technology, which we have cultivated and evolved over many years, features the ability to measure the pulse at high accuracy. This is done with ease just by wearing the device on the wrist.
Many small wristband heart rate monitors emit green LED light to the blood vessels in the skin and capture the reflected light that is not absorbed by hemoglobin with a photodetector. They then monitor minute changes in that amount of light to measure the pulse. We have achieved high-accuracy and low power consumption pulse measurement with sensing devices, which include photodetectors we have made using the semiconductor manufacturing technology and our own microelectromechanical systems (MEMS) technology.
We equip these photodetectors with two types of original optical filters - an angle limit filter and a spectral filter - to prevent deterioration in the measurement accuracy. This suppresses the impact from sunlight, room lights and other forms of ambient light to maintain measurement accuracy. Moreover, an accelerometer detects body motion noise caused by the swinging of arms and other movements. We then insert an algorithm that removes this noise to improve measurement accuracy.
Motion Sensing for Understanding Movements
Motion sensing is a solution to understand in what way and with how much force a person or object is moving. While it is possible to understand from images in what direction a person or object is moving, it's not easy to understand the speed or at how much force a person or object is moving. Gyro sensors, accelerometers and other sensing devices therefore serve an important role. Gyro sensors are also called angular velocity sensors. They detect the angular velocity (e.g., changes in rotation and direction). Accelerometers are devices that detect changes in the speed in the axial direction. They are installed in smartphones and handheld game consoles to detect the movements of the people operating them. They are also used to prevent camera shake.
Sensing Devices Contributing to Society
Sensing with an inertial measurement unit (IMU) that applies motion sensing is a way of understanding changes in the speed, attitude and direction of people and objects in three dimensions. IMUs detect at high accuracy inertial momentum that consist of a three-axis gyro sensor to understand changes in rotation and direction and a three-way accelerometer to understand changes in speed in the axial direction. These are mainly used to measure and control the behavior (attitude and trajectory) of moving bodies.
The accuracy of output data deteriorates under actual sensing environments because devices are affected by vibrations and temperature changes. However, IMUs are equipped with various corrective functions to reduce errors. This means they stably output highly accurate sensing data. IMUs are used in the attitude control of drones, small unmanned aircraft and small submersible vessels, in the automatic operation of agriculture machinery for large-scale farming, in control to safely operate construction machinery, and in the failure predictive maintenance of machines and devices.
In addition, the accelerometers installed in the IMUs are also equipped with frequency-changing accelerometer elements using crystal microfabrication technology. These feature low noise, high resolution and high stability. In addition to smartphones, games, cameras and other consumer electronic devices, high-performance accelerometers are also used in structural health monitoring systems to check the soundness of buildings and structures (e.g., bridges, elevated railroad tracks, roads, pipelines and large plants). These are used to measure changes in tilt, vibrations and pressure to predict the deterioration of buildings and social infrastructure.
We help solve issues in social infrastructure that were difficult to put into practical use (predictive maintenance, disaster monitoring, deterioration diagnosis, manpower-saving and efficiency improvement) with highly accurate sensing systems we have developed based on our original core technology. In this way, we will contribute to the realization of a convenient, safe and secure society.