The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Evangelos Papadopoulos - One of the best experts on this subject based on the ideXlab platform.
-
quadruped pronking on compliant terrains using a Reaction Wheel
International Conference on Robotics and Automation, 2016Co-Authors: Vasileios Vasilopoulos, Konstantinos Machairas, Evangelos PapadopoulosAbstract:While legged locomotion is a rapidly advancing area in robotics, several issues regarding the performance of such robots on deformable ground are still open. In this paper, we generate a pronking gait on a quadruped robot using a controller, which takes into account the effects of ground deformation. The controller, initially developed for monopods, is modified appropriately to operate for quadrupeds. The robot uses a Reaction Wheel to retain a desired body pitch. The dynamic models of leg motor drivetrains and of the Reaction Wheel are incorporated and their importance in the design of legged robots is highlighted. Simulation results show good performance in reaching commanded apex heights and forward velocities when traversing various deformable terrains, demonstrating that the developed controller is quite promising.
-
ICRA - Quadruped pronking on compliant terrains using a Reaction Wheel
2016 IEEE International Conference on Robotics and Automation (ICRA), 2016Co-Authors: Vasileios Vasilopoulos, Konstantinos Machairas, Evangelos PapadopoulosAbstract:While legged locomotion is a rapidly advancing area in robotics, several issues regarding the performance of such robots on deformable ground are still open. In this paper, we generate a pronking gait on a quadruped robot using a controller, which takes into account the effects of ground deformation. The controller, initially developed for monopods, is modified appropriately to operate for quadrupeds. The robot uses a Reaction Wheel to retain a desired body pitch. The dynamic models of leg motor drivetrains and of the Reaction Wheel are incorporated and their importance in the design of legged robots is highlighted. Simulation results show good performance in reaching commanded apex heights and forward velocities when traversing various deformable terrains, demonstrating that the developed controller is quite promising.
-
Minimum fuel techniques for a space robot simulator with a Reaction Wheel and PWM thrusters
2007 European Control Conference (ECC), 2007Co-Authors: Evangelos Papadopoulos, Ioannis K. Kaliakatsos, Dimitrios PsarrosAbstract:Space simulators offer engineers great advantages on studying space-related dynamic behavior without actually having to travel into space. They can test various control and design strategies, leading to close-to-optimal spacecraft missions. In this paper, an air-bearing planar space simulator developed for the experimental study of space robots on orbit is briefly presented. To achieve proportional control of 2-way on-off solenoid valves used for robot propulsion, a voltage PWM actuation is employed. The resulting thrust is analyzed, nonlinear valve effects are identified, and techniques tackling their shortcomings are proposed. The experimentally obtained thruster behavior is used to address a minimum fuel nozzle consumption problem during point-to-point robot motions. A comparison between the thruster-only propulsion method with one which includes a Reaction Wheel follows. A control algorithm for the simultaneous employment of thrusters and Reaction Wheel is presented. It is found that under certain assumptions, the use of a Reaction Wheel further minimizes fuel consumption, increasing the useful life of a space robot.
Kenji Uchiyama - One of the best experts on this subject based on the ideXlab platform.
-
ASCC - Attitude controller design for a small satellite using spherical Reaction Wheel system
2017 11th Asian Control Conference (ASCC), 2017Co-Authors: Ryo Takehana, Kenji UchiyamaAbstract:This paper proposes a design of a controller of the spherical Reaction Wheel system that was developed for a small satellite in our previous work. We confirmed its effectiveness as an attitude control system through experiments. The spherical Reaction Wheel system was proposed for miniaturizing a conventional Reaction Wheel system by applying a spherical rotor instead of flyWheels. Nevertheless, most of spherical Reaction Wheel systems tend to be huge due to difficulty of three dimensional rotation of a spherical rotor. Therefore, we proposed a new driving principle that uses diminutive DC motors for rotating a spherical rotor to develop a miniaturized system. Moreover, we confirmed that the principle achieves miniaturization of the system and has ability to control attitude of a satellite. However, the driving principle of the system has several problems that are friction wear of the system, stick-slip phenomenon, and an actuator dynamics. Firstly, we explain a system using omni-directional Wheels to decrease friction wear of the system. Then, we obtained mathematical model considering the effect of stick-slip phenomenon and actuator dynamics. The sliding mode controller is designed to eliminate these effects. Finally, the validity of the proposed controller is confirmed through numerical simulation. Moreover, an experimental equipment that is utilized to confirm effectiveness of the controller is also proposed.
-
Spherical Reaction Wheel System For Satellite Attitude Control
54th AIAA Aerospace Sciences Meeting, 2016Co-Authors: Hidehiko Paku, Ryo Takehana, Kenji UchiyamaAbstract:This paper presents results of control experiment conducted by using a novel satellite attitude control system, which is called Spherical Reaction Wheel controlled with sliding mode controller to confirm the validity of the system. The system that takes over the principle of conventional Reaction Wheel system is developed for miniaturizing an attitude control system by employing a spherical rotor instead of flyWheels. We have developed the spherical Reaction Wheel system using piezo electric actuators. The validity of the system as a satellite attitude control system has been confirmed by our previous work. Thus, we propose a new design of a spherical Reaction Wheel to improve the system and continue to further demonstrate the effectiveness of the system.
-
Satellite Attitude Control System Using a Spherical Reaction Wheel
Applied Mechanics and Materials, 2015Co-Authors: Hidehiko Paku, Kenji UchiyamaAbstract:A Reaction Wheel is generally capable of providing single axial torque. Three separated devices were indispensable for controlling three-axis attitude of a satellite. The proposed system, which is called spherical Reaction Wheel, enables three-dimensional rotation of a spherical rotor and provides three-dimensional torque so that mounting only one proposed device can be sufficient to control three-axis attitude of a satellite. Furthermore, the system reduces size and weight of an attitude control system in comparison with the conventional system. To confirm the validity of the proposed device as an attitude control system, we conduct experiments concerning attitude control of a small satellite model with PID controller.
-
Development of Three-Dimensional Reaction Wheel Using Spherical Rotor
AIAA Guidance Navigation and Control Conference, 2012Co-Authors: Kai Masuda, Kenji UchiyamaAbstract:This paper describes the development of three-dimensional Reaction Wheel using a sphere. The system enables three-dimensional motion in terms of rotation of the spherical Wheel without mechanical constraints. The system consists of a spherical Wheel as a rotor, actuators composed of multilayer piezoelectric ceramics, and sensing system to measure rotational speed. Most of system to generate three-dimensional motion requires very complex mechanism using gears and links, and special mechanism. Using three piezoelectric actuators as stator, the proposed system reduces size and weight in comparison with conventional mechanical system. Optical sensors, which are assembled into the system, measure the angular velocity of the spherical Reaction Wheel in any direction. The developed Reaction Wheel system, therefore, can be applied to small satellites with inherent problems such as space and weight limits. A PID controller is used for control of direction and angular velocity of the spherical Wheel. The proposed system is successfully employed to drive the spherical Wheel up to 100 rpm.
Raffaello D'andrea - One of the best experts on this subject based on the ideXlab platform.
-
CDC - Nonlinear analysis and control of a Reaction Wheel-based 3D inverted pendulum
52nd IEEE Conference on Decision and Control, 2013Co-Authors: Michael Muehlebach, Gajamohan Mohanarajah, Raffaello D'andreaAbstract:This paper presents the nonlinear analysis and control design of the Cubli, a Reaction Wheel-based 3D inverted pendulum. Using the concept of generalized momenta, the key properties of a Reaction Wheel-based 3D inverted pendulum are compared to the properties of a 1D case in order to come up with a relatively simple and intuitive nonlinear controller. Finally, the proposed controller is implemented on the Cubli, and the experimental results are presented.
Michael Muehlebach - One of the best experts on this subject based on the ideXlab platform.
-
nonlinear analysis and control of a Reaction Wheel based 3d inverted pendulum
Conference on Decision and Control, 2013Co-Authors: Michael Muehlebach, Gajamohan Mohanarajah, Raffaello DandreaAbstract:This paper presents the nonlinear analysis and control design of the Cubli, a Reaction Wheel-based 3D inverted pendulum. Using the concept of generalized momenta, the key properties of a Reaction Wheel-based 3D inverted pendulum are compared to the properties of a 1D case in order to come up with a relatively simple and intuitive nonlinear controller. Finally, the proposed controller is implemented on the Cubli, and the experimental results are presented.
-
CDC - Nonlinear analysis and control of a Reaction Wheel-based 3D inverted pendulum
52nd IEEE Conference on Decision and Control, 2013Co-Authors: Michael Muehlebach, Gajamohan Mohanarajah, Raffaello D'andreaAbstract:This paper presents the nonlinear analysis and control design of the Cubli, a Reaction Wheel-based 3D inverted pendulum. Using the concept of generalized momenta, the key properties of a Reaction Wheel-based 3D inverted pendulum are compared to the properties of a 1D case in order to come up with a relatively simple and intuitive nonlinear controller. Finally, the proposed controller is implemented on the Cubli, and the experimental results are presented.
Vasileios Vasilopoulos - One of the best experts on this subject based on the ideXlab platform.
-
quadruped pronking on compliant terrains using a Reaction Wheel
International Conference on Robotics and Automation, 2016Co-Authors: Vasileios Vasilopoulos, Konstantinos Machairas, Evangelos PapadopoulosAbstract:While legged locomotion is a rapidly advancing area in robotics, several issues regarding the performance of such robots on deformable ground are still open. In this paper, we generate a pronking gait on a quadruped robot using a controller, which takes into account the effects of ground deformation. The controller, initially developed for monopods, is modified appropriately to operate for quadrupeds. The robot uses a Reaction Wheel to retain a desired body pitch. The dynamic models of leg motor drivetrains and of the Reaction Wheel are incorporated and their importance in the design of legged robots is highlighted. Simulation results show good performance in reaching commanded apex heights and forward velocities when traversing various deformable terrains, demonstrating that the developed controller is quite promising.
-
ICRA - Quadruped pronking on compliant terrains using a Reaction Wheel
2016 IEEE International Conference on Robotics and Automation (ICRA), 2016Co-Authors: Vasileios Vasilopoulos, Konstantinos Machairas, Evangelos PapadopoulosAbstract:While legged locomotion is a rapidly advancing area in robotics, several issues regarding the performance of such robots on deformable ground are still open. In this paper, we generate a pronking gait on a quadruped robot using a controller, which takes into account the effects of ground deformation. The controller, initially developed for monopods, is modified appropriately to operate for quadrupeds. The robot uses a Reaction Wheel to retain a desired body pitch. The dynamic models of leg motor drivetrains and of the Reaction Wheel are incorporated and their importance in the design of legged robots is highlighted. Simulation results show good performance in reaching commanded apex heights and forward velocities when traversing various deformable terrains, demonstrating that the developed controller is quite promising.
