Jim+Briggs


 * Motion sensing technology **
 * Executive summary **


 * Motion sensing has become a boom in the various consumer electronic devices and the competitive landscape is significantly changing. One of the current goals of the technology is to relay computational and communication capabilities from the traditional computer and into everyday object and devices – to make them smart devices. The key function of smart devices is motion sensing. A gadget has a sense of its motion and position. This capability can allow cameras to record their positions along with the captured image and pencils to recall what they just have drawn, and golf balls to communicate to a golfer on how much power they used and their swings. As technology becomes better, common devices such as toys, games and clothing are given computational sensing and communicational abilities. This report provides a technological assessment of inertial sensing as the center of motion sensing. When devices are embedded with inertia sensors, they are capable of sensing their own orientations, motion and reacting accordingly and that’s when they refer to these devices as inertial proprioceptive devices. **
 * Motion sensing is not a new idea, for year it has been used in security systems, weapon systems, entertainment and medical systems. Automobiles and aircrafts have measured their motion for decades using varying electromechanical sensors as well as inertial sensors. There are two broad categories of inertial sensing devices accounting for a great majority of sensor sales: electromechanical that use solid inertial mass as sensing element and laser and fiber optic devices that utilize certain property of lasers to detect motions. **


 * Technology description **


 * Devices with this self-motion-sensing ability can monitor their motions and respond to them. Let put into consideration a personal digital assistant (PDA) containing inertial sensors. Such a device could allow its users to move through complex information spaces by physically moving or tilting the PDA in the corresponding direction. Moreover, an inertial-sensing user controlled device with a sense of its own functionality could assess its state and give its users proper feedback. Inertial sensors consist of accelerometers, IMU and gyroscopes, commonly shortened to gyros. Two types of sensors comprise inertial-sensing: accelerometers and gyroscopes. Accelerometers sense and respond to translational accelerations; gyroscopes sense and respond to rotational rates. Inertial sensors are desirable for general motion sensing because they operate regardless of external references, friction, winds, directions, and dimensions. However, inertial systems are not well-suited for absolute position tracking. In such systems, positions are found by integrating, over time, the signals of the sensors as well as any signal errors. As a result, position errors accumulate. Inertial systems are most effective in sensing applications involving relative motion. **


 * An accelerometer measures specific force and a gyroscope measures angular rate, both without an external reference. Accelerometer reacts to many types of movement while include liner and centripedal acceleration, gravity and vibration. Currently, there is a high supply of inexpensive accelerometers. Because of their range of uses and low cost, engineers always prefer accelerometers the most when designing a motion sensing device. **
 * Gyroscope, also called angular rate sensors, measure how fast an objects rotate. There are two branches of gyroscope: design mechanical gyros that operate using the inertial properties of matter, and optical gyros that operate using properties of light. According to Wikipedia, MEMS-based gyroscopes are used in portable electronic devices such as Apple's current generation of iPad and iPhone .Application of the output of gyroscope is a voltage proportional to the angular rate of rotation measured in millivolts per degree per second. **


 * Costs and benefits **


 * With the advancement of silicon and micromachining fabrication techniques, both gyroscope and accelerometer have become available for use in the consumer markets. This new technology is geared to towards low life-circle cost, small size and low production cost and large volume production. In the next few years, as inertial sensors continue to drastically become smaller, consumer less power and decrease in price, application and devices for motion recognition will evolve to become a low cost standardized product. A key influence on inertial sensor development is external aiding. External aiding is normally required to achieve accuracy. Another way of looking at this is that external aiding the inertial system allows less accuracy and therefore less costly inertial sensors to be used. Optical gyros are typically more expensive that mechanical gyros, and recently they are been used for navigational applications. **


 * Complementary technologies **


 * The technological evolution of inertia sensor and inertial navigation systems where complementary in nature. Accelerometers are used for measuring gravity gradient, seismic signals, levels and vibration. Whereas gyros are used for steering and stabilizing ships, missiles, cameras and binoculars. currently many consumer gadget and games industry are heavy relying on inertia technology to improve motion technology and most industrialist are predicting that the future of most consumer goods will be mostly a complement of inertia technology. **
 * Technology adoption recommendations **
 * This technology continues to drive and enable new components that are smaller, more reliable, efficient and lower in cost, benefiting consumers with a wide variety of new products and applications. This has been observed in handheld devices, game industry and most of the consumer goods. Recently the primary focus of the technology has been to make ordinary object smarter and at a very low cost. That is embedded into toys, games, tools and even clothing. One important sensing attribute is motion sensing, Products like pens and cameras or even shoes knowing their own motion would enable this products to perform at their own level. By tapping into this market while adopting this technology, the commercial production of such products would be in unbelievable demand. **


 * Reference **
 * Bose, Amitava, and Somnath Puri. Modern inertial sensors and systems. New Delhi: PHI Learning, 20092008. Print. **
 *  [] **
 *  [] **
 *  [] **
 *  [|http://www.cs.cmu.edu/~motionplanning/papers/sbp_papers/integrated2/verplaetse_inertial.pdf] **