The intellectual sensor. It weighs 3g and measures 20 x 25 x 4mm.
Demonstration of partial screen display using inertial sensors
A variety of products including Nintendo Co Ltd's "Wii" game console, NTT DoCoMo Inc's "DoCoMo2.0" mobile phones, Apple Inc's mobile devices and multimedia players have already applied motion sensing to their user interfaces.
Motion sensing is generally realized by two methods, namely the MEMS (microelectromechanical system) method using acceleration and angular velocity sensors and the other method that comprehends motion from changes in images of surroundings captured by CCD, CMOS and other camera systems. Nikkei Microdevices interviewed Hiroshi Usuda of Usuda Research Institute & Systems Corporation Ltd, who has been involved in the development of both methods, about their features.
Usuda and Usuda Research Institute released the "intellectual sensor (UBN-800)" module featuring a 7-axis inertial sensor (consisting of a triaxial acceleration sensor, a biaxial angular velocity sensor and a biaxial geomagnetic sensor) in this spring. If installed in devices such as mobile phones, this module can detect how the user is moving the device.
In addition, the module can output signals so they can represent the user's intention as accurately as possible, Usuda said.
This module can realize an application for viewing a large 2,000-inch screen display using a small 2-inch display. The small mobile phone display shows the large screen display as if part of it has been cut out.
If you move the handset to the right, the screen display will also scroll to the right with the right side of the image gradually appearing. You can see an entire large screen display in this manner. It is also allows you to enlarge or shrink the image by moving the handset back and forth.
In addition to inertial sensors, images captured by mobile phone cameras can be used for motion sensing as well. If motion sensing is based on this method, the cost can be generally kept low as there is no need to add new hardware to the mobile phone.
Hence, it is quite likely that this method will become the mainstream motion sensing technology in the future. In fact, when looking back on the history of audio and communication processing areas of mobile phones and PCs, software processing became mainstream as microcontrollers' processing performance rose.
Nevertheless, Usuda did not employ this camera-based method for a reason. He pointed out that speeds are limited using the camera-based image processing method. This method generally takes in an image and processes it every 1/30 second. As it can take in no more than 30 signals per second no matter how high the processor's performance is, the method cannot make the device comprehend motions accurately.
In contrast, inertial sensors allow tens of thousands of signals to be processed every second. The technology, therefore, allows more accurate recognition of motions.
Usuda worked for Sony Corp until 2005, where he conducted a research and development to capture the motion of a user's hand with a camera and apply the data to a user interface. He understood the limits of the camera-based method through his experiences there and decided to employ the inertial sensor-based method, he said.
Usuda first experienced MEMS-based inertial sensors around 2000 when he was still at Sony. Hitachi Metals Ltd came to show him a sample MEMS sensor it had developed, he said. Becoming confident about the significant potential of MEMS sensor, he has been advocating development using MEMS sensors.
He seems to have been involved in developing the "003" (mobile equipment), an unused model number, of Sony's "QUALIA" luxury AV equipment brand. Usuda had been developing his method until Sony resolved to terminate the commercialization of QUALIA products following the "Sony Shock."
The intellectual sensor that Usuda Research Institute released this spring uses Hitachi Metals' acceleration and geomagnetic sensors. The company has not revealed details of the angular velocity sensor, though.
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