Design, Modelling, and Control Strategies of a Three Degrees-of-Freedom VR Spherical Motor Part I: Reluctance Force Characterization

1992 ◽  
pp. 73-109
Author(s):  
Kok-Meng Lee
Keyword(s):  
Degrees Of Freedom ◽  
Control Strategies ◽  
Spherical Motor ◽  
And Control ◽  
Three Degrees Of Freedom

Simulation of Helicopter Powerplant Performance

1978 ◽  
Author(s):  
B. V. Baxendale ◽  
M. E. Inglis
Keyword(s):  
Power Plants ◽  
Degrees Of Freedom ◽  
Vertical Plane ◽  
System Failure ◽  
Flight Data ◽  
Rotor Systems ◽  
Hybrid Computer ◽  
And Control ◽  
Three Degrees Of Freedom ◽  
Proper Account

Programs have been written for a hybrid computer to simulate in real time the dynamic behavior of the engines, airframe, and rotor systems of the Sea King and Lynx helicopters; their purpose is to aid the study of performance and control of helicopter power plants. Since the engines are directly coupled to the lift-producing surface (the rotor), it is important to take proper account of the interactions between the power plant and the rest of the aircraft; however, for this type of work, it is reasonable to limit simulated aircraft maneuvers to three degrees of freedom in a single vertical plane. The method of simulating the major features of the helicopter are discussed, along with their implementation on the hybrid computer. The paper goes on to describe the successful validation of the two models by comparison with specially obtained flight data on a range of rapid maneuvers involving large changes in power demands. Finally, a description is given of an exercise on the Sea King simulation to investigate the effect of an engine or control system failure at a critical flight condition.

scholarly journals Guidance Navigation and Control for Autonomous Multiple Spacecraft Assembly: Analysis and Experimentation

2011 ◽  
Vol 2011 ◽  
pp. 1-18 ◽  
Author(s):  
Riccardo Bevilacqua ◽  
Marcello Romano ◽  
Fabio Curti ◽  
Andrew P. Caprari ◽  
Veronica Pellegrini
Keyword(s):  
Degrees Of Freedom ◽  
Control Strategies ◽  
Guidance And Control ◽  
Navigation And Control ◽  
Rotational Degrees Of Freedom ◽  
Multiple Spacecraft ◽  
Three Degree Of Freedom ◽  
Extra State ◽  
And Control ◽  
Spacecraft Assembly

This work introduces theoretical developments and experimental verification for Guidance, Navigation, and Control of autonomous multiple spacecraft assembly. We here address the in-plane orbital assembly case, where two translational and one rotational degrees of freedom are considered. Each spacecraft involved in the assembly is both chaser and target at the same time. The guidance and control strategies are LQR-based, designed to take into account the evolving shape and mass properties of the assembling spacecraft. Each spacecraft runs symmetric algorithms. The relative navigation is based on augmenting the target's state vector by introducing, as extra state components, the target's control inputs. By using the proposed navigation method, a chaser spacecraft can estimate the relative position, the attitude and the control inputs of a target spacecraft, flying in its proximity. The proposed approaches are successfully validated via hardware-in-the-loop experimentation, using four autonomous three-degree-of-freedom robotic spacecraft simulators, floating on a flat floor.

Optimal Backstepping Control of a VR Spherical Motor

2000 ◽  
Author(s):  
Kok-Meng Lee ◽  
Raye Sosseh
Keyword(s):  
Degrees Of Freedom ◽  
Control Design ◽  
Design Tool ◽  
Spherical Motor ◽  
Lyapunov Techniques ◽  
Variable Reluctance ◽  
Output Torque ◽  
Minimum Total Energy ◽  
Overall Stability ◽  
Three Degrees Of Freedom

Abstract This paper considers the control of a variable reluctance (VR) spherical motor that offers some unique features by combining the roll, pitch and yaw motion in a single joint. The 3-DOF VR motor has multiple independent inputs, and the output torque is direction varying and orientation-dependent and as a result, the control for such a motor is significantly more challenging than the single-axis motor. We formulate a new three-degrees-of-freedom (3-DOF) VR motor control design tool using backstepping, where the inputs are optimized to achieve minimum total energy consumed. The torque has been derived as a linear combination of the square of the input currents, a form computationally friendlier than its quadratic counterpart for real-time implementation. The overall stability of the system is shown using Lyapunov techniques. Simulation results are illustrated to show the performance of the controller.

Robust Trajectory Following Control of Robotic Systems

1985 ◽  
Vol 107 (4) ◽  
pp. 308-315 ◽  
Author(s):  
S. N. Singh ◽  
A. A. Schy
Keyword(s):  
Degrees Of Freedom ◽  
Digital Simulation ◽  
Robotic Systems ◽  
Control Law ◽  
Robot Arm ◽  
Control Laws ◽  
Payload Uncertainty ◽  
Trajectory Following ◽  
And Control ◽  
Three Degrees Of Freedom

Using an inversion approach we derive a control law for trajectory following of robotic systems. A servocompensator is used around the inner decoupled loop for robustness to uncertainty in the system. These results are applied to trajectory control of a three-degrees-of-freedom robot arm and control laws Cθ and CH for joint angle and position trajectory following, respectively, are derived. Digital simulation results are presented to show the rapid trajectory following capability of the controller in spite of payload uncertainty.

Trajectory Control of an Automated Guided Vehicle Using Feedback Linearization

2006 ◽  
Author(s):  
S. M. Mehdi Ansarey M. ◽  
M. J. Mahjoob
Keyword(s):  
Control System ◽  
Feedback Linearization ◽  
Degrees Of Freedom ◽  
Automated Guided Vehicle ◽  
State Variables ◽  
Discrete Curvatures ◽  
Steering Mechanism ◽  
Dynamics And Control ◽  
And Control ◽  
Three Degrees Of Freedom

In this paper, the dynamics and control of an automated guided vehicle (AGV) is described. The objective is to control the vehicle direction and location with respect to a prescribed trajectory. This is accomplished based on an optimum control strategy using vehicle state variables. A four-wheel vehicle with three degrees of freedom including longitudinal, lateral and yaw motion is considered. The nonlinearity of the tire and steering mechanism is also included. The control system design for circular, straight forward and composite path is presented based on feedback linearization. Some trajectory simulation for discrete curvatures is carried out. The controller was implemented within MATLAB environment. The design was also evaluated using ADAMS full vehicle assembly. The results demonstrated the accuracy of the model and the effectiveness of the developed control system.

A Spherical DC Servo Motor With Three Degrees of Freedom

1989 ◽  
Vol 111 (3) ◽  
pp. 398-402 ◽  
Author(s):  
K. Kaneko ◽  
I. Yamada ◽  
K. Itao
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Matrix Elements ◽  
Servo Motor ◽  
Constant Matrix ◽  
Spherical Motor ◽  
The Matrix ◽  
Three Degrees Of Freedom

A spherical DC servo motor with three degrees of freedom is proposed. First, the process of generating three-dimensional torque is analyzed to obtain the torque constant matrix. The matrix elements are shown to vary with rotor inclination, and winding currents are shown to interfere with each other. Then, the dynamics of the spherical motor are investigated theoretically and experimentally, considering torque interference, gyro moment and gravity. Finally, the trajectory of the prototype motor is shown in order to clarify its abilities. This new spherical motor is expected to produce a smaller, a lighter mechanism, since no gears or linkages are needed.

scholarly journals Control-Oriented Finger Kinematic Model: Geometry-Based Approach

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Jong-Seob Won ◽  
Nina Robson
Keyword(s):  
Degrees Of Freedom ◽  
Control Strategies ◽  
Kinematic Model ◽  
Systems Design ◽  
Single Parameter ◽  
Human Hand ◽  
Cylindrical Object ◽  
Proposed Model ◽  
Human Finger ◽  
And Control

Abstract This paper proposes a novel finger kinematic model for human hand configurations, which applies to the realization of a naturalistic human finger motion for robotic finger systems and artificial hands. The proposed finger model is derived based on the geometry of a hand shape grasping a virtual cylindrical object. The model is capable of describing the natural rotation configuration of the joints of a long finger with three degrees of freedom by a single parameter, i.e., the radius of a cylindrical object. Experimental validation of the model shows that it can simulate closely naturalistic human finger movements. With the use of the proposed model, discussions were made on how to achieve multifinger coordination that makes task-specific hand movements or a posture for specific hand actions. Due to the simplicity of the model to define joints angle configuration in a long finger by a single parameter, the combination of the proposed model and the multifinger coordination concept discussed can be seen as an inclusive framework in human-like hand systems design and control. This paper is the first step toward exploring future novel combined design–control strategies for the development of under-actuated prosthetic and powered orthotic devices for the naturalistic motion that are based on both Cartesian space trajectory tracking and joint angle coordination.

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