• Title/Summary/Keyword: SSMR

Search Result 2, Processing Time 0.017 seconds

Indoor Navigation of a Skid Steering Mobile Robot Via Friction Compensation and Map Matching (마찰 보상과 지도 정합에 의한 미끄럼 조향 이동로봇의 실내 주행)

  • So, Chang Ju;Lyou, Joon
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.19 no.5
    • /
    • pp.468-472
    • /
    • 2013
  • This paper deals with the indoor localization problem for a SSMR (Skid Steering Mobile Robot) subjected to wheel-ground friction and with one LRF (Laser Range Finder). In order to compensate for some friction effect, a friction related coefficient is estimated by the recursive least square algorithm and appended to the maneuvering command. Also to reduce odometric information based localization errors, the lines are extracted with scan points of LRF and matched with the ones of the corresponding map built in advance. The present friction compensation and scan map matching schemes have been applied to a laboratory SSMR, and experimental results are given to validate the localization performance along an indoor corridor.

A Study on Development of Safety Management Evaluation Index for Shipping Company (해운선사 안전관리 평가지표 개발에 관한 연구)

  • Kim, Hwa-Young
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.19 no.6
    • /
    • pp.629-636
    • /
    • 2013
  • There is no safety evaluation index with marine accidents and information of ship's safety management result for good grasp of safety management level of shipping company and effective monitoring. In this paper, we proposed a SMEI(Safety Management Evaluation Index) for evaluation of shipping companies. The SMEI is consist of MAR(marine accidents ratio), SSMR(ship safety management ratio) and SAP(safety advantage point) through brainstorming of the expert group and AHP(analysis hierarchy process)in previous study. And weights of SMEI are calculated using experts's opinions through the Delphi method. We also verified the validity of proposed SMEI to 119 Korean shipping companies with 916 ocean-going ships of Korean flag, which grouped three part (small, mid and big) by number of ship and gross tonnage. And we found out 19 shipping companies, 8 companies in group1 & group2 respectively and 3 companies in group 3, with score below 1.0 by SMEI. In these companies, there are no marine accidents in recent 3 years and appeared low frequency remarkably in the detention and mojor non-conformity by data analysis.