A recent trend towards greater automation of earth-moving machines such as dozers, loaders and backhoes reflects a larger movement in the construction industry to improve efficiency. This document reviews related work in various disciplines drawn upon by researchers-soil mechanics, computer graphics, remote sensing/control, kinematics of machines, dynamics, statistics, optimization and decision theory. In conclusion, this paper examines various automated excavators and classifies them by their level of autonomy.

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In order to improve disc cutter life on TBMs, a series of studies, which consistedof investigation on wear characteristics of disc cutters in situ, construction of a wear model for disc cutters and suggestion of a method for disc cutter life improvement, were conducted.
From the examination and analysis of disc cutter wear on TBMs in two tunneling sites, it was shown that disc cutter life is dependent on its position (cutting radius) on the cutter head. Rolling distance per unit wear of disc cutters near the center of the cutter head is extremely shorter than ones in the other positions. The edge shape of a worn cutter is also dependent on its position.
These characteristics can be explained well by the model based on skid between a disc cutter and rock. In cutters near the center of a cutter head, the life is much shorter and the wear on the outside face of the disc is outstanding because lateral skid is much predominant.
As a method to decrease the wear induced by skid, the offset arrangement of disc cutters was suggested and the equation for the optimum offset condition was derived. It was calculated that the cutter life might be elongated up to twice by the optimum offset arrangement.

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In order to automate the scooping task, it is desired that the resistive forces acting on the bucket are obtained in advance prior to the scooping task. Therefore, some models to predict the resistive forces acting on the bucket were proposed already. But, many parameters such as the friction coefficient between the bucket and the rocks, the angle of internal friction, slope of the rock pile and rock density are necessary to calculate the resistive force from these models. However, these parameters are generally unknown before the task. Therefore, the machine needs to obtain these parameters autonomously
The purpose of this study is to obtain the friction coefficient between the bucket and the rocks, the angle of internal friction and particle diameters by using the resistive forces which are measured at the beginning of the task.
In this study, the resistive forces were measured and the empirical equations to estimate the friction coefficient between the bucket and the rocks, the angle of internal friction and particle diameters were obtained. Furthermore, the method to judge the existence of huge rock in the pile was proposed by use of these equations.

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The present paper describes new sensory systems and algorithms for an underground mining machine to be located when it moves along an arbitrary path. Two sensory systems were devised using commercially available sensors which are highly reliable and hold stable performance: one consists of a gyroscopic angular velocity sensor and two servo-accelerometers, and the other replaces accelerometers by a couple of clinometers. The calculating method for locating the position of a mining machine comprises two consecutive procedures. The first part determines the attitude of the machine from the outputs from three sensors. The attitude is first derived from the generalized rotation matrix, then represented in terms of roll, pitch and yaw. The following part estimates the location of the machine step by step using its attitude and incremental distance.
A laboratory experiment showed that the location of a mini-vehicle which was measured by means of new sensory systems coincided with its position which was located by a reckoning method using a couple of wire-displacement transducers. This implys that the new sensory systems and related algorithms should have potential use for instrumentation of underground mining equipments.

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A laboratory scale experiment was carried out in order to examine the various spectra resulting from rock drilling noises. The experiment showed that the shaft of boring machine was characteristically excited by the rock drilling, and the strongest correlation was observed between the spectra of drilling noises and the properties of rock, namely compressive strength, tensile strength and shore hardness.

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A wheel loader is one of the major loading machine in surface mines. This paper describes the path planning which is a part of the research on automatic loading operation by a wheel loader. At loading operation, loader moves on V-shape path from scooping point to dumping point. A wheel loader has the articulated structure and steering is controlled by change of articulate angle. The path planning method for V-shape is proposed.
Major contents of this paper are as follows;
1) Kinematics of the articulate steering mechanism is analyzed. The relation between the steering angle and the curvature of path is almost liner.
(2) V-shape can be composed of two straight lines and the turn path which is a combination of four pseudo clothoid paths. For given position and direction of loader at scooping point and dumping point, length of the straight lines and the shape of turn path are determined by the proposed method. Example of V-shape generation for piled ore model is shown.
(3) For tracking control, the proposed control system includes the reference values generator. In path planning, control values are represented by function of moving distance. During tracking control, the reference values at each time are generated based on measured moving distance, and issued to the controller.

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Six rocks were subjected to CO₂ laser beam in preliminary experiment. A rock sample subjected to CO₂ laser was cut on a plane perpendicular to cutting surface, and kerf was carefully examined. A sandstone, a tuff and a andesite were found to be mostly melted and partly vaporized. A granite and a dolomite failed with many fractures around kerf filled with molten rock.
Further study was conducted for a granite and a sandstone where laser power, traverse speed and beam width on rock surface were taken as parameters. With increase of power of laser and decrease of traverse speed, depth of kerf and specific kerfing energy increased. When laser was exposed on rock, at the bottom of the kerf was the molten rock, and excessive energy of laser was consumed to vaporize a part of molten rock. So high intensity of laser energy caused the increase of specific kerfing energy.
Excavated volume of sandstone increased linearly with power of laser, and specific energy was approximately maintained to be constant. The excavated volume of granite also increased linearly with power of laser when power of laser was relatively low. However, with high power of laser such as 10 kW, the fractured zone spreaded over 31-10cm around the molten rock, so the excavated volume rapidly increased with power of laser, and the specific energy decreased sharply.
Several trials were made to remove molten rock and to increase the efficiency. With the help of air jet, molten rock was removed and the kerf depth increased by approximately 20%. When the kerf, however, reached a certain depth, molten rock was no more removed, so the cutting efficiency decreased.

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One of the most important goals for drilling contractors is to reduce drilling costs while maintaining strict safety standards.
In Japan, contractors usually use spindle type core drills for mineral resources and rotary table rigs for geothermal or oil & gas drilling. Recently, there have been several Japanese contractors who have tried to use top drive machines imported from the U. S. A. or Canada to drill hot spring wells.
These contractors have met with good results in shortening drilling time.
As a result of our efforts to improve drilling efficiency and safety, we have developed the newly designed Speed-SPA-Drill “SSD-Series” drilling machines.
The top head drive Speed-SPA-Drill has made possible remarkable reductions in working times for rigging up as well as tripping of drill pipes and casings.
Time reductions of about 40% and fewer drilling crew members when compared to conventional method are just a few of the major advantages of the new Speed-SPA-Drills.

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The vertival shafts are used in the various field such as mining, civil construction, power plant, and etc. for the underground utilizations. Furthermore, these shafts have the possibility to be used for the new utilizations for the energy stock, the cosmic rays observations.
The following equipments developed by Mitsui Miike Machinery, are introduced.
1) The winding equipment for the opening of vertical deep shaft.
2) Excavation for the deep piling.
3) New type excavator for the opening of vertical shaft to be expand the piling bottoms.

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This report shows the tunnelling machine movement mainly for civil engineering works in Japan.
In these twenty years, various new tunnelling technology has been developed under the strong demands to utilize underground space of cities.
3 typical tunnelling machines-open TBM, EPB shield, Slurry type shield are introduced in this report.
Technical trends of tunelling machines are;
(1) Large diameter/deep location/long distance excavation
(2) Free sectional area (double circular, ellipse, changeable diameter, etc.)
(3) Start and docking technique
(4) Curve excavation
(5) ECL (Extruded Concrete Living)
(6) Automation
Acontinuous developing movement of tunl/elling machine hereafter can be predicted

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The largest bulldozer in the world, the D575A Super Dozer, has been developed and achieved 70-100% more dozing production and 5-15% less overall cost per production than the largest conventional bulldozer in the large surface mine. The new design concept of the Super Dozer has enabled us to get such high production and cost performance. First, the new concept dozing blade, the Super Blade, improves dozing efficiency because it reduces soil resistance and unbalance of ground pressure distribution while dozing, thus producing more dozing production per traction force. Second, the machine design is optimized for dozing application instead of compromising to take a balance between dozing and ripping application, where each requirement is usually incompatible. The D575A Super Dozers are now operated at surface coal mines in North America. High dozing capability and productivity are highly appreciated by customers.

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The production of KOMATSU HD 785-3, 78 ton class dump truck was started in 1988.
About 500 units of HD 785-3 were shipped to miners or constructors all of the world, but not only in domestic market. The reputation of this truck is high production and good reliability.
Recently, many customers of 78 ton class dump truck desire to upgrade their trucks in 100 ton class for more productivity.
KOMATSU HD 985-3 which has the larger size tires is developed with aim of the first truck in 100 ton class to meet the requirements raised at the meetings with the customers.

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Japan Crushed Stone Association was commissioned by Japan Small Business Corporation regarding the improvement and automation of the workplace environment for purposes of upgrading technology skills in the crushed stone industry as well as securing the [appropriate] work force. We are undertaking the technology development project with these goals in mind.
In the crushed stone industry, workers face an extremely rigorous environment where they must work outdoors for long hours. For this reason, it is difficult to secure new workers and presently we are suffering from a severe labor shortage.
The industry is also confronted with the problem of aging in the existing labor force.The operation of boring and transporting machinery requires skill, and with aging as a factor in the current labor shortage, there is an increasing need to develop easy-to-operate machinery or unmanned-operation machinery
Technical development is progressing in the following divisions:
Automatiom technologyom the crawler drill, under Furukawa Co., Ltd.
Automatiom techmologyon the wheelloader, umder Komatsu, Ltd.
Ummammed/operatiom techmology om the dump truck, umder Komatsu, Ltd.
Comprehemsive adjustment and mamagememt for the overall commissiomed project, under Japan Crushed Stone Association.
This technology development project was implemented on a projected three-year schedule beginning in 1994. To date, the development of basic functions is virtually complete.

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