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Incorporation of various types of sensors increases the degrees of autonomy and intelligence of mobile robots (mobots) in perceiving surroundings, which at the same time imposes a large computational burden on data processing. The purpose of the research presented in this paper is to develop a low-cost multisensor system and incidental algorithms for autonomous navigation of a mobot. This paper proposes digital image processing schemes for mapbuilding and localization of a mobot using a monocular vision system and a single ultrasonic sensor in indoor environments. In localization, the camera calibration is preceded so that the depth information can be acquired from the image obtained by a single camera. For map-building, fast and effective image processing techniques based on morphology are applied to reduce computational complexities. For preliminary experiments, we have integrated a mobot system whose main components are a mono-vision system, a single ultrasonic sensor, and a notebook PC, mounted on a mobile base. The proposed algorithms were implemented, and the mobot was able to localize itself in an allowed position error range and to locate dynamic obstacles moving reasonably fast inside a building. The overall results demonstrate the suitability of the proposed methods for developing autonomous service mobots in indoor environments.In particular, the exact and accurate map is essential as a model of environment for path planning and localization. Although the map can be constructed by human operators, it is very cumbersome to update the map when the map requires constant modification for frequently changing environment. The mapbuilding is an ancillary function of a mobot constructing a digital map based on its sensor measurements. Meanwhile, the purpose of perception of autonomous mobots in navigation is two-fold, localization and obstacle detection. While active localization requires pre-known artificial landmarks[2], passive localization detects structural features of environment using various sensors. Although vision is not necessary for most of mobot tasks, it is desirable for unstructured environments due to its long-range, high resolution, and passive sensing ability[3]. This paper presents a map-building scheme using single ultrasonic sensor, where an occupancy grid map is converted to a grayscale image and then various digital image processing techniques are applied to the image to extract spatial features and possible routes in indoor environment. It also describes simple but effective procedures of camera calibration and image processing techniques for localization using a mono-vision system. The localization includes a camera calibration process which enables the mobot to measure the range in a single image frame, and utilizes linear structural features in indoor environment such as doors and corridor lines. PATH PLANNING USING IMAGE PROCESSING 1. INTRODUCTIONOne of the most fundamental requirements for intelligence of autonomous mobots is the automated navigation skill of traveling from a curre...

In Pasir mine, coal seams and host rocks of varying thickness have been uniquely deposited with an average dip angle of 85°. The host rocks are weak and mainly composed of mudstone and sandstone comprising of 90-95% of the total pit volume. The thickness of coal seams and host rocks ranges from sub-metric to few tenths of meter. The overall safe pit slope angle was evaluated to be 27°for mining depth of 50-150 m. Several slopes failure incidents have occurred in the mine causing considerable disruption in production and monetary loss. It is envisaged that slope failures may be triggered due to blasting conducted in steeply dipping stratified deposit. In order to investigate the causes of slope failures, peak particle velocity (PPV) and accelerations at various locations from the blast site have been measured. In addition, finite element models of pit slope have been analyzed by applying static or gravity loading as well as blasting or dynamic loading. This paper elaborates the results of in situ measurements of ground vibration and numerical investigation and suggests possible causes of slope failures in Pasir mine.

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