Feasibility Study on an Excavation-Type Demining Robot

It is said that 60 70 million mines are currently laid in over 50 countries throughout the world (Shimoi, 2002). These mines not only injure people directly, but also negatively influence the lives of inhabitants and restoration of the economy because of their consequent restriction of farmland. Such mines are categorized into two types: ATMs (anti-tank mines) and APMs (anti-personnel mines). The purpose of ATMs is to destroy tanks and vehicles, while that of the APMs is to injure or kill people. The APMs are cheap to produce, while APM removal is quite expensive. Also, the APMs maintain their destructive power for a long time. To mitigate the current tragic situation, an urgent “humanitarian demining operation” (with a demining rate of more than 99.7%) is now required all over the world (Shimoi, 2002). The demining work mainly depends on hazardous manual removal by humans; it presents serious safety and efficiency issues. For increased safety and efficiency, some large-sized machines have been developed. For example, the German MgM Rotar rotates a cylindrical cage attached in front of the body and separates mines from soil (Geneva International Centre for Humanitarian Demining, 2002; Shibata, 2001). The RHINO Earth Tiller, also made in Germany, has a large-sized rotor in front of the body; it crushes mines while tilling soil (see Fig. 1). The advantages of MgM Rotar and RHINO are a high clearance capability (99%) and high efficiency respectively. In Japan, Yamanashi Hitachi Construction Machinery Co., Ltd. has developed a demining machine based on a hydraulic shovel. A rotary cutter attached to the end of the arm destroys mines; the cutter is also used for cutting grasses and bushes. Although many machines with various techniques have been developed, a comprehensive solution that is superior to human manual removal remains elusive. Salient problems are the demining rate, limitation of demining area (MgM Rotar), prohibitive weight and limitation of mine type (RHINO Earth Tiller), and demining efficiency (MgM Rotar, and the demining machine made by Yamanashi Hitachi Construction Machinery Co., Ltd.). Because those machines are operated manually or by remote control, expert operators are required for each machine. Also, working hours are limited. Recently, various demining robots have been developing mainly at universities. Hirose et al. have developed a probe-type mine detecting sensor that replaces a conventional prod (Kama et al., 2000). It increases safety and reliability. They have also developed a quadruped walking robot, some snake-type robots, mechanical master-slave hands to remove landmines, and robotic system with pantograph manipulator (Hirose et al., 2001a;