Façade cleaning in high-rise buildings has always been considered a hazardous task when carried out by labor forces. Even though numerous studies have focused on the development of glass façade cleaning systems, the available technologies in this domain are limited and their performances are broadly affected by the frames that connect the glass panels. These frames generally act as a barrier for the glass façade cleaning robots to cross over from one glass panel to another, which leads to a performance degradation in terms of area coverage. We present a new class of façade cleaning robot with a biped mechanism that is able overcome these obstacles to maximize its area coverage. The developed robot uses active suction cups to adhere to glass walls and adopts mechanical linkage to navigate the glass surface to perform cleaning. This research addresses the design challenges in realizing the developed robot. Its control system consists of inverse kinematics, a fifth polynomial interpolation, and sequential control. Experiments were conducted in a real scenario, and the results indicate that the developed robot achieves significantly higher coverage performance by overcoming both negative and positive obstacles in a glass panel.

The façade cleaning of high rise buildings is one of the hazardous tasks that is performed by human operators. Even after a significant advancement in construction technologies, several newfangled skyscrapers are still using the manual method for cleaning the glass panels. This research is aimed at the development of a glass façade cleaning robot, capable of adapting to any kind of building architecture. A robotic system capable of cleaning vertical glass surfaces demands a transformable morphology. A self-reconfigurable robot is one of the potential solutions to realize high degrees of adaptability. Following the design principles we derived, we propose a nested reconfigurable design approach for glass façade cleaning and develope a system of robot modules that performs glass façade cleaning. Throughout this research article, we discuss the brief concept and scheme of nested reconfigurable design principle and the hardware-software challenges associated with it. This article also discusses the capability to maximize the flexibility and modularity of the robot by using intra- and inter-reconfigurations. The effectiveness of the designed system is verified by experimental means.

In this study, trajectory-tracking control for a lizard-inspired single-actuated robot (LISA) is implemented using a novel morphology. A high degree of reproducibility is obtained between the results of kinematic analysis and the behavior of the actual robot. Several 1-degree-of-freedom (DOF)-driven robots have been proposed. However, the application of these robots is severely restricted because of their inherent morphology limitations. LISA is a multilegged robot that can overcome these disadvantages and propel and turn with 1-DOF. In this study, we formulate the kinematics, such as the turning angle and stride length, of LISA. Furthermore, a unique robot coordinate is defined to enable the symmetrical representation of critical robot state quantities. Next, a trajectory-tracking control system based on the proportional-integral-derivative (PID) control is designed, and it is verified by both experiments and numerical simulations. Finally, the results of the experiments and numerical simulations are quantitatively compared according to the root mean square, and the reproducibility of the kinematics analysis and the behavior of the actual system are discussed. This study makes the following contributions: (1) The morphology of LISA facilitates analytical results with only kinematic analysis, which is considerably simpler than dynamics analysis. (2) LISA achieved sufficiently good kinematic performance for the required motions. Experiments revealed that the designed trajectory-tracking control system allows for LISA to appropriately track several types of trajectories.

The purpose of this paper is to design a lizard-inspired robot driven by a single actuator. Lizard-inspired robots in previous studies had the issue of slippage of their supporting legs. To overcome this issue, a lizard-inspired robot consisting of a four-bar linkage mechanism was designed. The purpose of this paper was achieved through three processes. The first process was kinematic analysis, where the turning angle and stride length of the robot were analyzed. The kinematic analysis results were verified via numerical simulations. The second process was the design and fabrication of the robot. For the robot’s design, both a shuffle-walking method utilizing a claw-shaped leg mechanism and a sliding-rod mechanism for equipping the actuator on the robot’s own coordinates were designed. The third process was experimental verification. The first experimental result was that the claw-shaped leg mechanism was capable of generating an 85.26 N difference in the static frictional force in the longitudinal direction. The other three experimental results were that the robot was capable of driving with 3.51%, 3.16%, and 3.53% error compared to the kinematic analyses, respectively.

This paper presents an approach to the estimation of a window shape for increasing the adaptability of glass façade-cleaning robots to different buildings. For this approach, a window scanning robot equipped with a 2D laser range scanner installed perpendicularly to a window surface is developed for the testbed, and a method for the window shape estimation is proposed, which consists of the robot’s pose estimation with an extended Kalman filter (EKF) and the loop closure based on the robot’s pose estimated. The effectiveness of the proposed approach is demonstrated through an experiment that is carried out on a window placed on a floor. The experimental results show that the window scanning robot can acquire a window shape, moving on a window surface, and the proposed approach is effective in increasing the accuracy of the window shape estimation.