Plasma-assisted polishing (PAP) as a damage-free and highly efficient polishing technique has been widely applied to difficult-to-machine wide-gap semiconductor materials such as 4H-SiC (0001) and GaN (0001). In this study, a 20-mm square large mosaic single crystal diamond (SCD) substrate synthesized by microwave plasma chemical vapor deposition (CVD) was polished by PAP. Argon-based plasma containing oxygen was used in PAP to modify the surface of quartz glass polishing plate, and a high material removal rate (MRR) of 13.3 μm/h was obtained. The flatness of SCD polished by PAP measured by an interferometer was 0.5 μm. The surface roughness measured by both scanning white light interferometer (SWLI) (84-μm square) and atomic force microscope (AFM) (5-μm square) was less than 0.5 nm Sq. The micro-Raman spectroscopy measurement results of mosaic SCD substrate processed by PAP showed that residual stress and non-diamond components on the surface after PAP processing were below the detection limit.

Odometry is widely used to localize wheeled and tracked vehicles because of its simplicity and continuity. Odometric calculations integrate the wheel or track's rotation speed. The accuracy of position thus calculated, is affected by slippage between the ground and the wheel or track. When traveling on a loose slope, the localization accuracy of the odometry decreases remarkably due to slippage. To improve its accuracy in such environments, terramechanics focus on estimating the interaction between a vehicle and the ground. However, because these formulas are complicated and governed by many terrain-specific parameters, they are difficult to use in unknown environments. In this study, we propose slip estimation methods targeted toward use in unknown environments. We consider four types of slippage, based on the slippage direction and maneuver type. Longitudinal and lateral slippage occurring during straight maneuvering are derived by approximating the terramechanics slip model. In contrast, for turning maneuvers, longitudinal slippage is derived from an empirical equation for the relationship between slip ratio and input velocity, and lateral slippage is obtained from a regression function. We also proposed slip-compensated odometry, which applies the slip model to the kinematics of a skid-steering vehicle. To evaluate the proposed slip model and slip-compensated odometry, we conduct several experiments with a skid-steering tracked vehicle on an indoor sandy slope. Experimental results confirmed that position estimation accuracy was improved by introducing slip-compensated odometry compared to conventional odometry. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

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ABSTRACT:In present the unmanned construction system technology is adapted on initial operation against of the disaster occasion. For instance it has been used in Unzen.It depends on the scale and site situation of disaster which system should be applied to.A lot of remote control technology of operating construction machinery has been developed as that technology.Underwater bulldozer was developed in 1968、which is a start of the technology.Recently the remote control technology has been applied to restoration works for digging、loading and transportation after the eruption of Unzen.The present study verifies it concerning the operativeness of a remote system that offers the site information by the monitor and operates it.In the research, it has aimed at the operativeness improvement, the working efficiency improvement、and the tiredness decrease. Arrangement and the operation of the monitor are researched now. Moreover, we do the examination for the system improvement in the future.In this report, the operation experimentation of 'Remote control in the site 'and' Remote control systems that displayed the monitor and operated the site information' (two kinds of systems) was done.And, it is the one that the ability and the behavior pattern that recognized the space of the operator were verified.

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At present, the Unmanned Construction System (UCS) is adapted on initial operation against the disaster. For instance, it has been used in Unzen. When the scale of the disaster is big, or the danger to a person is big, the UCS is expected as a quick and safe construction technology. The Remote Controlled UCS is introduced into construction site to repair earth-fill embankment or to remove rock, as urgent measures after the disaster outbreak. For improvement of the operability, shortening of the skill time, reduction of the fatigue, examination of the most suitable system (placement of a monitor and the joy stick) of the remote system is a main theme in the Public Works Research Institute (PWRI). In the report of this year, when the operator controls construction machine directly or he controls it using remote system (he can check the situation of site only via monitor), the degree of achievement, construction efficiency and construction precision were inspected. The remote system which is based on the system used at Unzen was developed at PWRI.