Spherical Robot Research Articles

The Design and Development of a Dynamic Model of a Low-Power Consumption, Two-Pendulum Spherical Robot

This article discusses the design, development, and energy consumption of a power-efficient spherical robot. The boosted performance of the robot is due to the separation between the lateral and longitudinal motions. This two-pendulum Innovative Spherical Robot (ISR) is 11% more energy efficient than those of similar one-pendulum models. The complex and nonlinear dynamic model of this nonholonomic robot is accurately derived by employing the Euler–Lagrange method from three considered points of masses. By resorting to experimental tests, the results of the dynamic models simulations are presented and verified. Through some carefully designed and carried-out experiments, the maneuverability of the ISR is demonstrated. Some specific curvature lanes are devised to measure the energy consumption of the model. As indicated by the experimental results, the maximum cruise time obtained by the ISR is 220 min, which means 7 km range that suggests an appreciable ability for the long-term runs.

The Kinematics and Dynamics Motion Analysis of a Spherical Robot

The Kinematics and Dynamics Motion Analysis of a Spherical Robot

The Kinematics and Dynamics Motion Analysis of a Spherical Robot

The Kinematics and Dynamics Motion Analysis of a Spherical Robot

Geometric Kinematic Control of a Spherical Rolling Robot

We give a geometric account of kinematic control of a spherical rolling robot controlled by two internal wheels just like the toy robot Sphero. Particularly, we introduce the notion of shape space and fibers to the system by exploiting its symmetry and the principal bundle structure of its configuration space; the shape space encodes the rotational angles of the wheels, whereas each fiber encodes the translational and rotational configurations of the robot for a particular shape. We show that the system is fiber controllable—meaning any translational and rotational configuration modulo shapes is reachable—as well as find exact expressions of the geometric phase or holonomy under some particular controls. We also solve an optimal control problem of the spherical robot, show that it is completely integrable, and find an explicit solution of the problem.

Design, modeling and experimental evaluation of a legged, multi-vectored water-jet composite driving mechanism for an amphibious spherical robot

This paper designs a novel legged, multi-vectored water-jet composite driving mechanism (LMWCDM) for the amphibious spherical robot (ASRobot) and presents modeling and experimental evaluation of this composite driving mechanism. In order to crawl on land flexibly, the robot was designed in SolidWorks and simulated in ADAMS environment with the sit to stand motion and a crawling gait. Then the simulation results, such as driving torques, guided the selection of servomotors in different joints. In aquatic environment, the dynamic modeling of ASRobot was analyzed by synthesizing the propulsive vectors of four propellers in each workspace of legs. Simplistically, multiple underwater locomotion, such as longitudinal and lateral motion, rotary motion, sinking and floating motion and cruising motion, were proposed. Thus, using a six-axis force/torque sensor at the equivalent mass center, a force and torque measuring mechanism was developed to obtain the direct propulsive effect and validate the modeling of the driving system. To evaluate the robot design and selection of servomotors, experiments of the sit to stand motion and crawling motion were conducted. Underwater testing experiments of LMWCDM were carried out to verify the modeling of rotary motion, sinking and floating motion. Besides, underwater test of the robot prototype also proved the highly flexible and swift motion.

Variable-model SMA-driven spherical robot

In this paper, we introduce a bionic spherical robot. This research has been inspired by the muscular organs and modularity of organisms such as starfish and octopuses. The robot that we fabricated uses five soft feet to crawl like a starfish, and the robotic feet are driven by the shape memory alloy springs. The robotic spherical structure and the soft feet were fabricated by 3D printing. The robotic feet were made of silicone gel; these feet could bend upward and downward to help the robot to crawl on the ground and roll down a slope. The shell separation module installed inside the robot could divide the robot into two identical modules, and this smart structure could enhance the robotic flexibility in a small space. We performed force analysis and robotic simulation, and the results verified the feasibility of the model. The robot can switch between rigidity and softness by using human control. Three types of gaits have been proposed for controlling robotic movement and improving robotic flexibility in movement; these include rolling, crawling, and avoiding obstacles. The results of this study indicate that the variable-model design of the robot is an effective way to enhance the flexibility of soft robots.

DESIGN AND CONSTRUCTION OF A NEW GENERATION OF ROBOTS

Each robot that is part of the physical environment, should be able to interact with humans. The dynamic balance on the robots such as the spherical robot cause demonstration Various interactive behaviors. Spherical robot is a stable and dynamic moving robot. It only features a spherical wheel that enables it to move in all directions, so there is not a problem to overturn the standing robots because its motion is in the form of rolling. The robot is able to easily move between the glades, sand and snow without clinging and can be used to build special operations teams in war zones or even carry explosives to the enemy's base. This research, is about the kinematics of the optimal motion of a spherical robot in a direct path with a simple mechanism and check spherical robot's control by the computer, and how wireless communication is communicated through the module. This robot is more capable than other robots made with different movement mechanisms, so that it can be easily moved and smooth in smooth, fluid, slippery, and angular surfaces, without the need for an attachment to move, It just moves easily with the gravity of the earth. The propulsion mechanism of this robot is a pendulum of two degrees of freedom propelled by two engines. This robot is a non-holonomic and non-linear system, so it needs a nonlinear controller like Sliding Mode Control (SMC).

Performance evaluation of spherical robot for amphibious applications

Aiming at exploration tasks in complex amphibious environments, our previous researches proposed and developed an amphibious spherical robot, and the robot is capable of motion on land and swim in underwater. In this paper, focus on robotic applications on various terrains of amphibious robot, three quadruped gaits and an adaptive control method were designed, implemented and evaluated for our amphibious spherical robot. Firstly, a simplified locomotion model of the amphibious spherical robot was established, and three types of on-land locomotion gait were designed for the robot, then the adopted gait was adaptively adjusted with attitude compensation of robot. And simultaneously, an adaptive control algorithm was designed to control the amphibious spherical robot in underwater environment, which has good robustness and adaptability of disturbances in underwater environment. Finally, some amphibious evaluation experiments on robotic on-land and underwater motion performance indicated that the amphibious spherical robot was capable of moving stably on-land and in underwater environments, which enhanced its mobility and viability.

The inverse kinematics of rolling contact of timelike curves lying on timelike surfaces

Rolling contact between two surfaces plays an important role in robotics and engineering such as spherical robots, single wheel robots, and multi-fingered robotic hands to drive a moving surface on a fixed surface. The rolling contact pairs have one, two, or three degrees of freedom (DOFs) consisting of angular velocity components. Rolling contact motion can be divided into two categories: spin-rolling motion and pure-rolling motion. Spin-rolling motion has three (DOFs), and pure-rolling motion has two (DOFs). Further, it is well known that the contact kinematics can be divided into two categories: forward kinematics and inverse kinematics. In this paper, we investigate the inverse kinematics of spin-rolling motion without sliding of one timelike surface on another timelike surface in the direction of timelike unit tangent vectors of their timelike trajectory curves by determining the desired motion and the coordinates of the contact point on each surface. We get three nonlinear algebraic equations as inputs by using curvature theory in Lorentzian geometry. These equations can be reduced as a univariate polynomial of degree six by applying the Darboux frame method. This polynomial enables us to obtain rapid and accurate numerical root approximations and to analyze the rolling rate as an output. Moreover, we obtain another outputs: the rolling direction and the compensatory spin rate.

Robust RGB-D Camera and IMU Fusion-based Cooperative and Relative Close-range Localization for Multiple Turtle-inspired Amphibious Spherical Robots

In the narrow, submarine, unstructured environment, the present localization approaches, such as GPS measurement, dead-reckoning, acoustic positioning, artificial landmarks-based method, are hard to be used for multiple small-scale underwater robots. Therefore, this paper proposes a novel RGB-D camera and Inertial Measurement Unit (IMU) fusion-based cooperative and relative close-range localization approach for special environments, such as underwater caves. Owing to the rotation movement with zero-radius, the cooperative localization of Multiple Turtle-inspired Amphibious Spherical Robot (MTASRs) is realized. Firstly, we present an efficient Histogram of Oriented Gradient (HOG) and Color Names (CNs) fusion feature extracted from color images of TASRs. Then, by training Support Vector Machine (SVM) classifier with this fusion feature, an automatic recognition method of TASRs is developed. Secondly, RGB-D camera-based measurement model is obtained by the depth map. In order to realize the cooperative and relative close-range localization of MTASRs, the MTASRs model is established with RGB-D camera and IMU. Finally, the depth measurement in water is corrected and the efficiency of RGB-D camera for underwater application is validated. Then experiments of our proposed localization method with three robots were conducted and the results verified the feasibility of the proposed method for MTASRs.

Design and test of stem diameter inspection spherical robot

Stem diameter is an important parameter in the process of plant growth which can indicate the growth state and moisture content of the plant, its automatic detection is necessary. Traditional devices have many drawbacks that limit their practical uses in general case. To solve those problems, a stem diameter inspection spherical robot was developed in this study. The particular mechanism of the robot has turned out to be suitable for performing monitoring tasks in greenhouse mainly due to its spherical shape, small size, low weight and traction system that do not produce soil compacting or erosion. The mechanical structure and hardware architecture of the spherical robot were described, the algorithm based on binocular stereo vision was developed to measure the stem diameter of the plant. The effectiveness of the prototype robot was confirmed by field experiments in a tomato greenhouse. The results showed that the machine measurement data was linearly correlated with the manual measurement data with R2 of 0.9503. There was no significant difference for each attribute between machine measurement data and manual measurement data (sig > 0.05). The results showed that this method was feasible for nondestructive testing of the stem diameter of greenhouse plants. Keywords: stem diameter inspection, spherical robot, binocular stereo vision, Census transform DOI: 10.25165/j.ijabe.20191202.4163 Citation: Quan L Z, Chen C, Li Y J, Qiao Y J, Xi D J, Zhang T Y, et al. Design and test of stem diameter inspection spherical robot. Int J Agric & Biol Eng, 2019; 12(2): 141–151.

Controlling the Locomotion of Spherical Robots or Why BB-8 Works

Abstract Spherical robots have a wide range of self-propulsion mechanisms. Of particular interest in this paper are propulsion systems where wheels are placed in contact with the inner surface of the spherical shell of the robot. Here, locomotion is achieved by a combination of the actions of the motors along with the rolling constraints at the point of contact of the shell with the ground surface. We ask and seek the answer to the following question using elementary arguments: What is the minimal number of actuations needed to completely prescribe the motion of the robot for the two distinct cases where it is rolling and sliding on a surface? We find that two points of actuation are all that is needed provided some simple geometric conditions are satisfied. Our analysis is then applied to the BB-8 robot to show how locomotion is achieved in this robot.

Desarrollo de un sistema mecatrónico para robot humanoide que permita emular el movimiento del cuello de los seres humanos

En el presente trabajo se muestra el diseño de un sistema mecatrónico, el cual emula los movimientos del cuello humano, ya que sostendrá la cabeza de un robot humanoide (Arthur) desarrollado por la empresa Hanson Robotics. El diseño mecánico se basa en un robot esférico de 3 grados de libertad (3-GDL), se desarrolla el modelo dinámico a través de las ecuaciones de movimiento de Euler-Lagrange. La etapa de control es una tarjeta de desarrollo FPGA (arreglos de compuertas programables en campo) de la familia Cyclone IV, la etapa de potencia se basa en transistores BJT, se implementa el controlador Tangente hiperbólico y una interfaz de comunicación WiFi para configurar el robot desde una PC con ayuda del software Labview. Como resultado se muestra la integración del sistema mecatrónico, la interfaz desarrollada junto con la comunicación FPGA-PC y control de posición. El trabajo futuro será la implementación del sistema en el robot humanoide.

Motion Control Analysis of a Spherical Robot as a Surveillance Robot

A robot is designed to be a helping tool for the human to work in the dirty, dull and dangerous environment, such as underwater, underground and disaster area. The most suitable type of robot for surveillance is a spherical robot. This type of robot has the ball-shaped, therefore minimize the contact to the ground, reduce friction, and energy consumption. All the components are shielded inside a shell; therefore it is possible to make this robot to be waterproof. One of the applications of this spherical robot is an industrial piping surveillance robot. The robot considered in this study is semi-autonomous where a user moves the robot through user interface installed in an android. The user can control the robot by examining the monitor. The input analysis of how the signal can move the robot is discussed in this paper. To prove the effectiveness of the proposed method, the robot is moved in an experimental setting including a pipe-like tunnel to test it. The robot moved and controlled smoothly, and it can maintain the position of the camera (robot head) always up to ensure the clear vision for the user.

Hydrodynamic Analysis-Based Modeling and Experimental Verification of a New Water-Jet Thruster for an Amphibious Spherical Robot.

Thrusters are the bottom actuators of the amphibious spherical robot, and play an important role in the motion control of these robots. To realize accurate motion control, a thrust model for a new water-jet thruster based on hydrodynamic analyses is proposed in this paper. First, the hydrodynamic characteristics of the new thruster were numerically analyzed using computational fluid dynamics (CFD) commercial software CFX. The moving reference frame (MRF) technique was utilized to simulate propeller rotation. In particular, the hydrodynamics of the thruster were studied not only in the axial flow but also in oblique flow. Then, the basic framework of the thrust model was built according to hydromechanics theory. Parameters in the basic framework were identified through the results of the hydrodynamic simulation. Finally, a series of relevant experiments were conducted to verify the accuracy of the thrust model. These proved that the thrust model-based simulation results agreed well with the experimental results. The maximum error between the experimental results and simulation results was only 7%, which indicates that the thrust model is precise enough to be utilized in the motion control of amphibious spherical robots.

Stabilization of the motion of a spherical robot using feedbacks

• Spherical robot moves by changing the position of its center of mass and by changing gyrostatic momentum. • Stabilization of the spherical robot using only two control actions. • Tuning of controllers for stabilization of spherical robot of combined type. The paper is concerned with the problem of stabilizing a spherical robot of combined type during its motion. The focus is on the application of feedback for stabilization of the robot which is an example of an underactuated system . The robot is set in motion by an internal wheeled platform with a rotor placed inside the sphere. The results of experimental investigations for a prototype of the spherical robot are presented.

Kinematics of Spherical Robots Rolling over 3D Terrains

Although the kinematics and dynamics of spherical robots (SRs) on flat horizontal and inclined 2D surfaces are thoroughly investigated, their rolling behavior on generic 3D terrains has remained unexplored. This paper derives the kinematics equations of the most common SR configurations rolling over 3D surfaces. First, the kinematics equations for a geometrical sphere rolling over a 3D surface are derived along with the characterization of the modeling method. Next, a brief review of current mechanical configurations of SRs is presented as well as a novel classification for SRs based on their kinematics. Then, considering the mechanical constraints of each category, the kinematics equations for each group of SRs are derived. Afterward, a path‐tracking method is utilized for a desired 3D trajectory. Finally, simulations are carried out to validate the developed models and the effectiveness of the proposed control scheme.

The Dynamics of a Spherical Robot of Combined Type by Periodic Control Actions

The Dynamics of a Spherical Robot of Combined Type by Periodic Control Actions

Optimal Trajectory Planning for Spherical Robot Using Evolutionary Algorithms

Abstract The trajectory planning problem of robot is addressed in this paper, which is consist of finding an optimal trajectory for a given path from an initial and final positions in the operating space. We aim to determine the optimal trajectory for three degrees of freedom spherical wrist with concurrent axis by using genetic algorithm. The optimized trajectory must have a minimum trajectory time and minimum joint traveling distance with free path collision in the workspace. In order to move from the initial point to the final point, we propose the use of polynomial interpolation, the optimization technique allow to determine the coefficients of the optimal trajectory. The simulation results for a three degrees of freedom robots are presented and discussed.

Design and test of stem diameter inspection spherical robot

Design and test of stem diameter inspection spherical robot