Spherical Rolling Robot Research Articles

Kinetic Model for a Spherical Rolling Robot with Soft Shell in a Beeline Motion

A simplified kinetic model called Spring Pendulum is developed for a spherical rolling robot with soft shell in order to meet the needs of attitude stabilization and controlling for the robot. The elasticity and plasticity of soft shell is represented by some uniform springs connected to the bracket in this model. The expression of the kinetic model is deduced from Newtonian mechanics principles. Testing data of the driving angle acquired from a prototype built by authors indicate that testing data curve accords to the theoretic kinetic characteristic curve, so the kinetic model is validated

ジャイロ搭載型球体ロボットの直進運動制御

This paper deals with the problem of controlling a spherical rolling robot that has a new driving mechanism equipped with a gyro. The translational motion of the robot is caused by transmission of angular momentum from the gyro to a spherical outer shell of the robot. A feedback controller that makes the robot achieve a straight motion is designed based on the equations of motion for the robot. The effectiveness of the controller is demonstrated by experimental results.

2A2-P09 慣性ロータを用いた球型移動ロボットの動作実験(特殊移動ロボット(2))

The paper describes the development of a spherical rolling robot actuated by internal rotors that are placed on three orthogonal axes. The driving principle for such a robot exploits non-holonomic constraints to propel the rolling carrier by using inertia of the rotors. The design of the robot with symmetrical placement of the rotors, keeping the total center of mass in the center of the sphere, is presented and initial experiments are reported.

On the dynamic model and motion planning for a spherical rolling robot actuated by orthogonal internal rotors

The paper deals with the dynamics of a spherical rolling robot actuated by internal rotors that are placed on orthogonal axes. The driving principle for such a robot exploits nonholonomic constraints to propel the rolling carrier. A full mathematical model as well as its reduced version are derived, and the inverse dynamics are addressed. It is shown that if the rotors are mounted on three orthogonal axes, any feasible kinematic trajectory of the rolling robot is dynamically realizable. For the case of only two rotors the conditions of controllability and dynamic realizability are established. It is shown that in moving the robot by tracing straight lines and circles in the contact plane the dynamically realizable trajectories are not represented by the circles on the sphere, which is a feature of the kinematic model of pure rolling. The implication of this fact to motion planning is explored under a case study. It is shown there that in maneuvering the robot by tracing circles on the sphere the dynamically realizable trajectories are essentially different from those resulted from kinematic models. The dynamic motion planning problem is then formulated in the optimal control settings, and properties of the optimal trajectories are illustrated under simulation.

Dynamics and Trajectory Tracking of a Spherical Rolling Robot on an Inclined Plane

In this paper, we derive the dynamics of a spherical rolling robot, called BYQ-III, rolling without slipping on an inclined plane through the constrained Lagrange method. We present a state space realization of this constrained system, and develop a control algorithm for stabilizing the robot to track a desired trajectory on the inclined plane based on input-output feedback linearization. The validity of the proposed control scheme is then verified through simulation study.

Adaptive Neuro-Fuzzy Control of a Spherical Rolling Robot Using Sliding-Mode-Control-Theory-Based Online Learning Algorithm

As a model is only an abstraction of the real system, unmodeled dynamics, parameter variations, and disturbances can result in poor performance of a conventional controller based on this model. In such cases, a conventional controller cannot remain well tuned. This paper presents the control of a spherical rolling robot by using an adaptive neuro-fuzzy controller in combination with a sliding-mode control (SMC)-theory-based learning algorithm. The proposed control structure consists of a neuro-fuzzy network and a conventional controller which is used to guarantee the asymptotic stability of the system in a compact space. The parameter updating rules of the neuro-fuzzy system using SMC theory are derived, and the stability of the learning is proven using a Lyapunov function. The simulation results show that the control scheme with the proposed SMC-theory-based learning algorithm is able to not only eliminate the steady-state error but also improve the transient response performance of the spherical rolling robot without knowing its dynamic equations.

Velocity Control of a Spherical Rolling Robot Using a Grey-PID Type Fuzzy Controller With an Adaptive Step Size

This paper proposes a grey-PID type fuzzy controller (GPIDFC) with an adaptive step size to control the velocity of a spherical rolling robot characterized by a highly nonlinear system model. The proposed control structure consists of a grey predictor and a PID type fuzzy controller (PIDFC). Another fuzzy controller is proposed to tune the step size of the grey predictor. The simulation results show that the PIDFC coupled to a grey predictor with an adaptive step size is able to control the spherical rolling robot with a better transient response, e.g. lower overshoot, when compared to a conventional PIDFC.

Dynamic Modeling and Simulation of the Internal- and External-Driven Spherical Robot

This paper describes a prototype and analytical studies of a spherical rolling robot, a new design of a nonholonomic robot system. The spherical robot is driven together by an internal linear motor, continuously changing the center of gravity, and external wind thrust. A mathematical model of the robot’s motion was developed using Maggi’s equations without the Lagrange’s multipliers from a view of the nonholonomic constraint. An obstacle avoidance experiment was carried out to analyze the law of motion of the robot driven three ways: external wind driven, internal motor driven, and a combination of both. The results demonstrate that the proposed dynamic model is valid for the spherical robots driven by the different ways for environmental exploration.

Modeling and control of a spherical rolling robot: a decoupled dynamics approach

SUMMARYThis paper presents the results of a study on the dynamical modeling, analysis, and control of a spherical rolling robot. The rolling mechanism consists of a 2-DOF pendulum located inside a spherical shell with freedom to rotate about the transverse and longitudinal axis. The kinematics of the model has been investigated through the classical methods with rotation matrices. Dynamic modeling of the system is based on the Euler–Lagrange formalism. Nonholonomic and highly nonlinear equations of motion have then been decomposed into two simpler subsystems through the decoupled dynamics approach. A feedback linearization loop with fuzzy controllers has been designed for the control of the decoupled dynamics. Rolling of the controlled mechanism over linear and curvilinear trajectories has been simulated by using the proposed decoupled dynamical model and feedback controllers. Analysis of radius of curvature over curvilinear trajectories has also been investigated.

Optimization of Contact Point Trajectory for a Spherical Rolling Robot

Optimization of Contact Point Trajectory for a Spherical Rolling Robot

1228 ジャイロ搭載型球体ロボットにおける外殻位置と内部ニューテーションの同時制御(GS-10 先端制御)

1228 ジャイロ搭載型球体ロボットにおける外殻位置と内部ニューテーションの同時制御(GS-10 先端制御)

Introducing Glory: A Novel Strategy for an Omnidirectional Spherical Rolling Robot

This paper describes a prototype and analytical studies of a spherical rolling robot, a new design of an omnidirectional robot system. The robot can arbitrarily begin to move in any direction to the target, and autonomously roll and reach any desired position. Our design has considered a spherical robot with an internal mechanism for propulsion. The propulsion mechanism will distribute weights radially along spokes fixed inside the sphere and enables the robot to accelerate, decelerate, and move with constant velocity. A mathematical model of the robot’s dynamic and motion was instructed. An algorithmic motion planning is developed and, partly, pseudocode of that is presented. For a number of missions, it is shown experimentally that the model agrees well with the results.

Spherical rolling robot: a design and motion planning studies

Describes a prototype and analytical studies of a spherical rolling robot, a new design of a nonholonomic robot system. The spherical robot is driven by two remotely controlled, internally mounted rotors that induce the ball to roll and spin on a flat surface. It is tracked on the plane by an overhead camera. A mathematical model of the robot's motion was developed using the nonholonomic constraints on its motion. For a number of simple motions, it is shown experimentally that the model agrees well with the results. Methods were developed for planning feasible, minimum time and minimum energy trajectories for the robot. These methods are illustrated both by mathematical simulation and hardware experiments.