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.

The Integrated Mission Simulator

SIMULATION ◽  
1964 ◽  
Vol 2 (2) ◽  
pp. R-9-R-23
Author(s):  
Edward E. Markson ◽  
John L. Stricker
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Landing Site ◽  
Euler Angle ◽  
Space Mission ◽  
Six Degrees Of Freedom ◽  
Guidance And Control ◽  
Manned Space ◽  
And Control ◽  
Guidance Technique

Space mission simulator programs may be divided into two broad categories: (1) training tools (quali tative devices often simulating a continuous mission), and (2) laboratory tools (quantitative devices treating the mission in phases, each phase being programmed separately to obtain optimum scaling). This paper describes the development of an analog program capable of continuously simulating an entire lunar mission in six degrees of freedom with high resolu tion throughout. The reported work logically traces the program development through the equations of motion, the guidance and control equations, and the analog mechanization. The translation equations are de veloped using a modified form of Encke's method; two reference origins are utilized at the two points of primary interest—the landing site and the target vehicle—such that the displacements are approach ing a minimum in the regions where the highest reso lution is required. The variables are rescaled as this region is approached to obtain maximum accuracy. Relays, stepping switches and diode gates are used for rescaling and to re-reference origins. A particular Euler angle sequence is selected based on matrix validity criteria applied to the mission. A previously reported guidance technique is shown to be appli cable to all phases of the mission. It is concluded that the method demonstrated in this paper leads to minimum computer loading for simulating a manned space mission without program discontinuities. Supporting data include an analog- computed trajectory representative of a long-dura tion mission, which is compared in detail with a digital solution.

Modeling and Visual Navigation of Autonomous Surface Vessels

2015 ◽  
pp. 662-696 ◽  
Author(s):  
Jian Hong Mei ◽  
Mohd Rizal Arshad
Keyword(s):  
Degrees Of Freedom ◽  
Vision System ◽  
Visual Navigation ◽  
Related Research ◽  
Guidance And Control ◽  
Surface Vessels ◽  
Research Problems ◽  
Research Findings ◽  
Increasing Demand ◽  
And Control

In this chapter, the authors address main issues of Navigation, Guidance, and Control (NGC) and vision system of Autonomous Surface Vessels (ASV). These issues compose research problems and related research findings in recent years. Related research results are reviewed first; then the hardware and subsystem of ASVs is introduced. For the typical rudder-propeller, three degrees of freedom horizontal underactuated model is presented. Visual ASV is applied more and more in complex and unknown environment with increasing demand of obstacles avoidance. Two examples of visual applications are demonstrated. One is riverbank identification using color segmentation and Hough Transform; the other is bridge detection using optical flow.

scholarly journals Guidance and Control of Position and Attitude for Rendezvous and Dock/Berthing with a Noncooperative/Target Spacecraft

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Gilberto Arantes ◽  
Luiz S. Martins-Filho
Keyword(s):  
Linear Quadratic Regulator ◽  
Linear Quadratic ◽  
Proximity Operations ◽  
Guidance And Control ◽  
Navigation And Control ◽  
Out Of Plane ◽  
Tracking Ability ◽  
And Control ◽  
Rendezvous And Docking ◽  
Target Spacecraft

Noncooperative target spacecrafts are those assets in orbit that cannot convey any information about their states (position, attitude, and velocities) or facilitate rendezvous and docking/berthing (RVD/B) process. Designing a guidance, navigation, and control (GNC) module for the chaser in a RVD/B mission with noncooperative target should be inevitably solved for on-orbit servicing technologies. The proximity operations and the guidance for achieving rendezvous problems are addressed in this paper. The out-of-plane maneuvers of proximity operations are explored with distinct subphases, including a chaser far approach in the target’s orbit to the first hold point and a closer approach to the final berthing location. Accordingly, guidance solutions are chosen for each subphase from the standard Hill based Closhessy-Willtshire (CW) solution, elliptical fly-around, and Glideslope algorithms. The control is based on a linear quadratic regulator approach (LQR). At the final berthing location, attitude tracker based on a proportional derivative (PD) form is tested to synchronize the chaser and target attitudes. The paper analyzes the performance of both controllers in terms of the tracking ability and the robustness. Finally, it prescribes any restrictions that may be imposed on the guidance during any subphase which can help to improve the controllers tracking ability.

scholarly journals An Advanced Guidance and Control System for an Unmanned Vessel with Azimuthal Thrusters

2018 ◽  
Author(s):  
M Bibuli ◽  
Ga Bruzzone ◽  
Gi Bruzzone ◽  
M Caccia ◽  
G Camporeale ◽  
...  
Keyword(s):  
Autonomous Navigation ◽  
Control Strategies ◽  
Vertical Axis ◽  
Control Loop ◽  
Guidance And Control ◽  
Marine Vehicles ◽  
Regulation Scheme ◽  
Control Scheme ◽  
Constrained Environments ◽  
And Control

The proposed paper presents the design and development of the combined guidance and control strategies for the autonomous navigation of an unmanned vessel characterized by azimuth-based thrust architecture. Autonomous Marine Vehicles (AMVs) are consolidates technological tools commonly employed for different tasks such as exploration, sampling and intervention. With the final aim of autonomous shipping, the capabilities of AMVs have to be migrated and adapted towards the reliable and safe control of commercial-like unmanned vessel, that are taking place thanks to a number of technological research projects. The employment of new concept hulls and thrust configurations, as for instance Small Waterplane Area Twin Hull (SWATH) combined with Azimuthal propulsion (common propeller-based thruster with the capability of 360◦ rotation around the vertical axis), requires robust guidance techniques to provide precise and reliable motion control during navigation. The paper proposes a dual-loop guidance and control scheme able to provide advanced navigation capabilities. In particular, the inner control loop, devoted to the actuation of the azimuthal thrusters, allows the tracking of reference course angle (namely the autopilot). Such a control loop is characterized by a modified PID regulation scheme, where a novel adaptive derivative component is inserted in order to improve the convergence curve towards the required course reference. The outer guidance loop, based on Lyapunov/virtual-target approach, allows the vessel to track generic desired paths, thus enhancing the autonomous navigation capabilities also in constrained environments. The paper will provide a deep design and analysis approach for the developed techniques, as well as simulation results of the combined guidance and control scheme, proving the reliability of the proposed approach in different operative conditions. Experimental results will be provided, depending on the availability of the actual autonomous vessel (currently under final development/test phases and related to the specific project activities). 

On the Lateral Stability and Control of the Automobile as Influenced by the Dynamics of the Steering System

1966 ◽  
Vol 88 (3) ◽  
pp. 283-294 ◽  
Author(s):  
Leonard Segel
Keyword(s):  
Degrees Of Freedom ◽  
Steering System ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Steering Wheel ◽  
Directional Control ◽  
Natural Modes Of Motion ◽  
Three Degree Of Freedom ◽  
And Control ◽  
Automobile Use

Measurements of the directional response of an automobile to torque inputs applied at the steering wheel are compared with predictions yielded by a five-degree-of-freedom model of a four-wheeled, pneumatic-tired vehicle. This comparison demonstrates that the directional control and stability of the “free-control” automobile is satisfactorily characterized by the addition of a quasilinear representation of a steering system (i.e., a mechanism having two degrees of freedom with Coulomb friction introduced as the single nonlinear element) to a linear three-degree-of-freedom representation of the “fixed-control” automobile. Use is made of the experimentally substantiated five-degree-of-freedom mathematical model to study the relationship between automotive design parameters and the response and stability in each of the four natural modes of motion that exist for the free-control vehicle.

Design of a Three-Degree-of-Freedom Robotic Worktable With Prescribed Entire-Motion Characteristics

1986 ◽  
Vol 108 (3) ◽  
pp. 373-380
Author(s):  
Jau-Jung Chen ◽  
A. DiBenedetto ◽  
E. Pennestri ◽  
Ting W. Lee
Keyword(s):  
Degrees Of Freedom ◽  
Design Parameters ◽  
Primary Interest ◽  
Analysis And Design ◽  
Flight Simulators ◽  
Transmission Angle ◽  
Rotational Degrees Of Freedom ◽  
Motion Characteristics ◽  
Three Degree Of Freedom ◽  
Four Bar Linkage

This paper presents the analysis and design of a robotic worktable with a structure based on two platforms connected by three four-bar linkages. The worktable has three rotational degrees-of-freedom and is designed for special motion generators, such as gyroscope calibration instruments and flight simulators. Of primary interest is the influence of the characteristics of a single four-bar linkage on the entire-motion characteristics of the worktable. This involves an investigation of the effects of limit positions, rotatability of cranks, transmission-angle characteristics and the variation of design parameters of the four-bar linkages on the characteristics of the compound platform mechanism. Based on the analytical results, some physical insights are interpreted and general guidelines can be drawn on the design of this robotic worktable with prescribed motion characteristics.

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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