A Single Unit Concept And Design Of A High Maneuverability Mobile Robot

The aim of this project is to design and produce a mobile robot as a tool that could replace humans to perform certain tasks such as search, inspection, navigation and rescue in hazardous environments. The mobile robot has the ability to move in the environment such as air, soil and water. Some types of mobile robots that have been widely developed such as legged robots, wheeled robot with no arms, wall climbing robot and robot amphibians. The mobile robot is also known as bio-inspired robot. Snake robot is one example of a mobile robot. Snake robots are suitable for environment that is very limited because of the small cross section and highly redundant kinematics enables them to enter and move through narrow spaces. Robot snake promising mechanism for real-world applications such as search and rescue in destroyed city and industrial inspection. The degree of freedom gives them the potential to adapt to complex environments for confined spaces. Snake robots offer advantages over traditional mobile robots because they provide properties that can be achieved especially in an environment that convoluted. Thus, a mobile robot is generated using CAD software systems of SolidWorks and a prototype is produced to test it abilities. Physical appliances that have been used are an Arduino UNO, servo motors, and other electrical equipment. After that, the functional test and mechanism of the snake robot prototype has been carried out

Task-Space Control of Articulated Mobile Robots With a Soft Gripper for Operations

A task-space method is presented for the control of a head-raising articulated mobile robot, allowing the trajectory tracking of a tip of a gripper located on the head of the robot in various operations, e.g., picking up an object and rotating a valve. If the robot cannot continue moving because it reaches a joint angle limit, the robot moves away from the joint limit and changes posture by switching the allocation of lifted/grounded wheels. An articulated mobile robot with a gripper that can grasp objects using jamming transition was developed, and experiments were conducted to demonstrate the effectiveness of the proposed controller in operations

Motion control of a snake robot moving between two non-parallel planes

A control method that makes the head of a snake robot follow an arbitrary trajectory on two non-parallel planes, including coexisting sloped and flat planes, is presented. We clarify an appropriate condition of contact between the robot and planes and design a controller for the part of the robot connecting the two planes that satisfies the contact condition. Assuming that the contact condition is satisfied, we derive a simplified model of the robot and design a controller for trajectory tracking of the robot’s head. The controller uses kinematic redundancy to avoid violating the limit of the joint angle and a collision between the robot and the edge of a plane. The effectiveness of the proposed method is demonstrated in experiments using an actual robot

Smooth control of an articulated mobile robot with switching constraints

The paper describes a smooth controller of an articulated mobile robot with switching constraints. The use of switching constraints associated with grounded/lifted wheels is an effective method of controlling various motions; e.g. the avoidance of a moving obstacle. A model of an articulated mobile robot that has active and passive wheels and active joints with switching constraints is derived. A controller that accomplishes the trajectory tracking of the robot’s head and subtasks using smooth joint input is proposed on the basis of the model. Simulations and experiments are presented to show the effectiveness of the proposed controller

Gait Design for a Snake Robot by Connecting Curve Segments and Experimental Demonstration

This paper presents a method for designing the gait of a snake robot that moves in a complicated environment. We propose a method for expressing the target form of a snake robot by connecting curve segments whose curvature and torsion are already known. Because the characteristics of each combined shape are clear, we can design the target form intuitively and approximate a snake robot configuration to this form with low computational cost. In addition, we propose two novel gaits for the snake robot as a design example of the proposed method. The first gait is aimed at moving over a flange on a pipe, while the other is the crawler gait aimed at moving over rough terrain. We demonstrated the effectiveness of the two gaits on a pipe and rough terrain in experiments

Control of an articulated wheeled mobile robot in pipes

We propose a control method in which an articulated wheeled mobile robot moves inside straight, curved and branched pipes. This control method allows the articulated wheeled mobile robot to inspect a larger area. The articulated wheeled mobile robot comprises pitch and yaw joints is and propelled by active wheels attached to the robot. Via the proposed control method, the robot takes on two different shapes; one prevents the robot from slipping inside straight pipes and the other allows movement in a pipe that curves in any direction. The robot is controlled by a simplified model for the robot\u27s joint angles. The joint angles of the robot are obtained by fitting to a continuous curve along the pipe path. In addition, the angular velocity of the robot\u27s active wheels is determined by a simplified model. The effectiveness of the proposed the control method was demonstrated with a physical implementation of the robot, and the robot was able to move inside straight, curved and branched pipes

Three-dimensional steering for an articulated mobile robot with prismatic joints with consideration of hardware limitations

The paper presents a three-dimensional steering method for an articulated mobile robot that contains links, rotational joints, prismatic joints, and active wheels. The robot can change the angles of its links using the rotational joints and vary the lengths of its links using the prismatic joints. The target motion of this robot is represented by a continuous curve and the motions of the joints and the wheels are calculated by fitting the entire robot to this target curve. The forward velocity of the robot\u27s head is adjusted to satisfy the hardware limitations of the robot; e.g. joint angle, joint velocity, and wheel velocity limitations. In addition, a terrain-following method is presented that considers the changes in the lengths of the links. An experimental articulated mobile robot was developed and experiments were carried out to demonstrate the effectiveness of the proposed method

Development of a folding arm on an articulated mobile robot for plant disaster prevention

In this work, we develop a folding arm on an articulated mobile robot to inspect an industrial plant. The design targets of the arm, its operations, measurement ability, and mobility, were set for the task of inspecting an industrial plant. To accomplish the targets, we designed the folding arm considering both accessibility to high locations and the mobility of the articulated mobile robot to which it is attached. The arm has links, joints, dummy wheels, and sensors and enables the robot to which it is attached to manipulate objects, e.g. rotating valves, opening a door, or inspecting by accessing high locations. In addition, changing the posture of the arm and touching the dummy wheel in the arm to the surrounding terrain can reduce any negative effect of the arm on the robot\u27s mobility when it encounters narrow spaces, stairs, steps, and trenches. The arm is controlled as a six degrees-of-freedom manipulator without redundancy by an operator who directly sets two joint angles. The effectiveness of the developed arm was demonstrated not only through experiments in a laboratory but also in a field test at the Plant Disaster Prevention Challenge of the World Robot Summit 2018

Development and field test of the articulated mobile robot T2 Snake-4 for plant disaster prevention

In this work, we develop an articulated mobile robot that can move in narrow spaces, climb stairs, gather information, and operate valves for plant disaster prevention. The robot can adopt a tall position using a folding arm and gather information using sensors mounted on the arm. In addition, this paper presents a stair climbing method using a single backward wave. This method enables the robot to climb stairs that have a short tread. The developed robot system is tested in a field test at the World Robot Summit 2018, and the lessons learned in the field test are discussed

Flexible-Robotic Reflector for Aerospace Applications

Existing dish based antennas tend to have geometric morphologic distortion in the surface due to drastic thermal changes common in the space environment. In this paper we present a new concept for a dynamic antenna specially designed for communication satellites. The suggested flexible-robotic antenna is based on a dual-reflector structure, where the subreflector has a complex surface shaping robotic mechanism allowing it to fix most of the morphologic errors in the main reflector. We have implemented a set of searching algorithms allowing the hyper redundant robotic subreflector to adapt its surface to the morphologic distortions in the main reflector. The suggested new antenna was constructed and tested in an RF room in which it was able to fix the loss caused by distortion in the main reflector to the original gain in less than an hour