This paper describes design and application of a novel counter-balancing stackable parallel mechanism. The stackable mechanism is designed by combining a five-bar and a couple of parallelograms. This design allows a compact design and wide workspace as compared to prior parallel type counter-balancing mechanisms. A linear geometry of this mechanism guarantees static balancing in the whole workspace. This mechanism was successfully applied to otologic.

Much attention has not been paid to analysis of the open-loop stability for gravity counter-balancing of parallel mechanisms or closed-chain mechanisms. The open-loop stability is crucial especially in passively counter-balanced mechanisms where no actuators are involved. Passive hands-on device is such an example. A general stiffness model is derived for general closed-chain mechanism including counter-weight model. As a measure of the open-loop stability, we employ the determinant of the stiffness matrix. A parallel mechanism having 3 translational DOF (degree of freedom) is employed as an exemplary device. An antagonistically counter-balancing is found the most stable method. We conduct dynamic simulation and experiment to confirm the open-loop stability of the system.

This paper deals with design and motion planning of a reconfigurable robot that can be used for inspection of 80-100 mm pipelines. This robot consists of two connecting modules and each module consists of three pairs of caterpillar, which is operated by micro DC motor. The robot is foldable by using an embedded four-bar mechanism and compression of a spring connected to the four-bar allows the robot to maintain contact with the wall of pipelines. Controlling the speed of each caterpillar independently provides a steering capability to go through elbow and T-branch. The robot system has been developed and the validity of this mechanism was proved by experimentation.

As the need of well-being life becomes popular, one of important issues is clean drinking water. Delivery of clean water from the main water fountain to the end user is very crucial. However, typical pipelines are being contaminated by rust and several chemicals. And thus the water being delivered to house is not trustful as the drinking water. Thus, cleaning and inspection of the in-house pipeline becomes an important issue. However, it is hard to find a small-sized motor adequate to the robot for the inspection of the in-house pipeline with diameter of 15 mm. Thus, this paper introduces a new semi-automatic pipeline inspection robotic system for small-sized pipelines. Three different types of inspection robot system were developed, which have different combination of sensors to realize SLAM. The robot system is carried by an extension cable, which is in advance being penetrated into the pipeline by a compressed air. The feasibility of the proposed SLAM using this semi-automatic pipeline inspection robotic system was verified through experimentation.