No abstract

In this paper, a calibration method for gyro bias that changes depending on the position of the IMU (inertial measurement unit) is proposed to improve the navigation performance of RLG-based RINS (ring-laser-gyro-based rotational inertial navigation system). RINS is a navigation device that compensates for the inertial sensor errors by utilizing the rotation of the IMU. In previous studies, the rotation scheme of the IMU is designed assuming that inertial sensor errors are not affected by position of the IMU. However, changes in temperature distribution, direction of gravity, and dithering according to the rotation of the IMU affect the inertial sensor errors, such as gyro bias. These errors could degrade the long-term navigation performance of RLG-based RINS. To deal with this problem, this paper proposed a compensation method of the gyro bias that changes depending on the position of the IMU. First, RINS is reviewed using a dual-axis 16-position rotation scheme and RLG. Next, the attitude error of RLG-based RINS is derived utilizing navigation equations. The effect of the gyro bias change caused by the change in the IMU attitude for the navigation performance of RINS is analyzed based on navigation equations and simulations. Finally, system-level indirect calibrations for the Z–axis up position and Z–axis down position are performed to calculate the gyro bias change caused by the IMU attitude. The accuracy of the proposed calibration method is verified by long-term navigation test. The test results show that the proposed calibration method improves the navigation performance of RINS compared with the conventional calibration method.

We are developing a projection unit in a three-step process involving our previously proposed fiber-scanning methods (first two steps, which have been completed) and another fiberscanning method, called cross-limit (X-Limit), we propose for this paper that provides high resolution, uniform brightness, and a rectangular display area, which are difficult with previous methods. The development of X-Limit is the third and final step in developing this projection unit.

We are developing a projector system with scanning fiber device and its control system. Our novel scanning systems of scanning fiber device provide high resolution, uniform brightness, and rectangular display area, which are difficult challenges in conventional scanning fiber device.

We developed driving waveforms for new single sustain system with Hi‐AD. We designed address breakdown voltage up to 270V from conventional 100V to obtain the wide driving margin. The cost of sustain and address circuits can be reduced 19% compared with the conventional dual sustain system.