Free-flying robots in space: an overview of dynamics modeling, planning and control

Robotica ◽  
2007 ◽  
Vol 25 (5) ◽  
pp. 537-547 ◽  
Author(s):  
S. Ali A. Moosavian ◽  
Evangelos Papadopoulos
Keyword(s):  
Control Strategies ◽  
Equations Of Motion ◽  
Experimental Studies ◽  
Robotic Manipulators ◽  
Microgravity Environment ◽  
Dynamics Modeling ◽  
Planning And Control ◽  
Fixed Base ◽  
And Control ◽  
Flying Robots

SUMMARYFree-flying space manipulator systems, in which robotic manipulators are mounted on a free-flying spacecraft, are envisioned for assembling, maintenance, repair, and contingency operations in space. Nevertheless, even for fixed-base systems, control of mechanical manipulators is a challenging task. This is due to strong nonlinearities in the equations of motion, and consequently different algorithms have been suggested to control end-effector motion or force, since the early research in robotic systems. In this paper, first a brief review of basic concepts of various algorithms in controlling robotic manipulators is introduced. Then, specific problems related to application of such systems in space and a microgravity environment is highlighted. Basic issues of kinematics and dynamics modeling of such systems, trajectory planning and control strategies, cooperation of multiple arm space free-flying robots, and finally, experimental studies and technological aspects of such systems with their specific limitations are discussed.

scholarly journals Motion control of non-fixed base robotic manipulators

Robotica ◽  
1999 ◽  
Vol 17 (2) ◽  
pp. 143-157 ◽  
Author(s):  
F.M. Carter ◽  
D.B. Cherchas
Keyword(s):  
Motion Control ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Robotic Manipulators ◽  
Inverse Kinematic ◽  
Experimental Simulation ◽  
Fixed Base ◽  
And Control ◽  
Trajectory Generator ◽  
Base Object

Robotic manipulators mounted on spacecraft experience a number of kinematic, dynamic, and control problems because the motion of the spacecraft is affected by the robot motion. In this paper, the general three dimensional equations of motion are derived for an n link manipulator mounted on a non-fixed base object. Instead of performing a single inverse kinematic calculation at the beginning of a movement to determine the required joint setpoints, multiple inverse kinematic updates are done throughout a movement. The updating sequence is determined by an optimal inverse kinematic updating algorithm. This motion control algorithm is based on experimental simulation results performed in Matlab and a set of performance indices that are used as guidelines. Simple PD joint controllers and a special joint trajectory generator are used for servoing the manipulator joints for a planar robot application. The derived motion control techniques incorporate the base motion without base motion control.

scholarly journals Simulative Assessment of Agent Based Production Planning and Control Strategies

Procedia CIRP ◽  
2016 ◽  
Vol 57 ◽  
pp. 439-444 ◽  
Author(s):  
Denis Kurle ◽  
Stefan Blume ◽  
Tobias Zurawski ◽  
Sebastian Thiede
Keyword(s):  
Production Planning ◽  
Control Strategies ◽  
Production Planning And Control ◽  
Agent Based ◽  
Planning And Control ◽  
And Control

Dynamics modeling and control of active track tensioning system for tracked vehicle

2019 ◽  
Vol 26 (11-12) ◽  
pp. 989-1000
Author(s):  
Pingxin Wang ◽  
Xiaoting Rui ◽  
Hailong Yu ◽  
Bo Li
Keyword(s):  
Control Strategies ◽  
Stable Range ◽  
Dynamics Modeling ◽  
Modeling And Control ◽  
Flow Equations ◽  
Ground Pressure ◽  
Coupling System ◽  
Hydraulic Mechanism ◽  
And Control ◽  
Peak Value

Track assemblies are widely used to reduce vehicles’ ground pressure and improve their off-road performance. During off-road, the track tension has a significant effect on the performance of the crawler driving system. Previous control strategies only make use of the motions of partial road wheels. This paper develops a logical improvement to govern the motion of the track tensioner by using all road wheels. First, a dynamic model of the hydraulic-mechanism coupling system is established using the transfer matrix method for multibody systems and pressure-flow equations. Then, in order to get the angle of the idler arm, a modeling method of wheel envelope perimeter is developed, which is based on the locations of all wheels. Simulation results indicate that the control system maintains the wheel envelope perimeter almost constant while road wheels swing and decrease the possibility of peel-off and breakage of the track. It alleviates the track repeated stretch and keeps the tension in a stable range to reduce the fatigue damage. The control strategy can effectively reduce the peak value of the upper track tension during a vehicle passing through obstacles. This study suggests that the active track tensioning system can be implemented to improve the driving properties of tracked vehicles.

Design and Analysis of a Multimodal Grasper Having Shape Conformity and Within-Hand Manipulation With Adjustable Contact Forces

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Nagamanikandan Govindan ◽  
Asokan Thondiyath
Keyword(s):  
Control Strategies ◽  
Low Cost ◽  
Active Surface ◽  
Force Sensor ◽  
Contact Forces ◽  
Geometrical Shape ◽  
Planning And Control ◽  
Control Scheme ◽  
And Control ◽  
Compact Mechanism

Abstract This paper presents the design, analysis, and testing of a novel multimodal grasper having the capabilities of shape conformation, within-hand manipulation, and a built-in compact mechanism to vary the forces at the contact surface. The proposed grasper has two important qualities: versatility and less complexity. The former refers to the ability to grasp a range of objects having different geometrical shape, size, and payload and perform in-hand manipulations such as rolling and sliding, and the latter refers to the uncomplicated design, and ease of planning and control strategies. Increasing the number of functions performed by the grasper to adapt to a variety of tasks in structured and unstructured environments without increasing the mechanical complexity is the main interest of this research. The proposed grasper consists of two hybrid jaws having a rigid inner structure encompassed by a flexible, active gripping surface. The flexibility of the active surface has been exploited to achieve shape conformation, and the same has been utilized with a compact mechanism, introduced in the jaws, to vary the contact forces while grasping and manipulating an object. Simple and scalable structure, compactness, low cost, and simple control scheme are the main features of the proposed design. Detailed kinematic and static analysis are presented to show the capability of the grasper to adjust and estimate the contact forces without using a force sensor. Experiments are conducted on the fabricated prototype to validate the different modes of operation and to evaluate the advantages of the proposed concept.

Spatiotemporal trends of Chagas disease-related mortality in the Northeast of Brazil, 2007–2017

Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1552-1558
Author(s):  
G. J. B. Sousa ◽  
M. S. Farias ◽  
V. R. F. Cestari ◽  
T. S. Garces ◽  
T. A. Maranhão ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Empirical Bayes ◽  
Control Strategies ◽  
Scan Statistics ◽  
Planning And Control ◽  
Spatiotemporal Trends ◽  
Local Moran ◽  
Brazilian Northeast ◽  
And Control ◽  
Global And Local

AbstractChagas disease (CD) is a neglected disease and endemic in Brazil. In the Brazilian Northeast Region, it affects millions of people. Therefore, it is necessary to identify the spatiotemporal trends of CD mortality in the Northeast of Brazil. This ecological study was designed, in which the unit of analysis was the municipality of the Brazilian northeast. The data source was the Information System of Mortality. It was calculated relative risk from socioeconomic characteristics. Mortality rates were smoothed by the Local Empirical Bayes method. Spatial dependency was analysed by the Global and Local Moran Index. Scan spatial statistics were also used. A total of 11 287 deaths by CD were notified in the study. An expressive parcel of this number was observed among 70-year-olds or more (n = 4381; 38.8%), no schooling (n = 4381; 38.8%), mixed-race (n = 4381; 62.3%), male (n = 6875; 60.9%). It was observed positive spatial autocorrelation, mostly in municipalities of the state of Bahia, Piauí (with high-high clusters), and Maranhão (with low-low clusters). The spatial scan statistics has presented a risk of mortality in 24 purely spatial clusters (P < 0.05). The study has identified the spatial pattern of CD mortality mostly in Bahia and Piauí, highlighting priority areas in planning and control strategies of the health services.

scholarly journals SYSTEM DYNAMICS MODELING FOR CONSTRUCTION MANAGEMENT RESEARCH: CRITICAL REVIEW AND FUTURE TRENDS

2019 ◽  
Vol 25 (8) ◽  
pp. 730-741 ◽  
Author(s):  
Mingqiang Liu ◽  
Yun Le ◽  
Yi Hu ◽  
Bo Xia ◽  
Martin Skitmore ◽  
...  
Keyword(s):  
System Dynamics ◽  
Strategic Management ◽  
Construction Management ◽  
State Of The Art ◽  
Project Planning ◽  
System Dynamics Modeling ◽  
Dynamics Modeling ◽  
Planning And Control ◽  
And Control ◽  
The Impact

As a result of growing complexities in the construction industry, system dynamics modeling (SDM) has been increasingly used in construction management (CM) research to explore complicated causal relationships at the various levels of construction and management processes. Given the rapid growth of SDM applications over the past two decades, a systematic review is needed to ascertain the state of the art and further trends in the area. This paper provides the results of a systematic analysis of 103 papers from 41 selected peer-reviewed journals from 1997 to 2016. The contributions of the papers are first analyzed, structured and formulated in terms of the year of publication, software involved, the combined use with other methods, and research design. With the assistance of the a keyword co-occurrence network analysis, eight research topics involving different internal and external complexities are identified, including: (1) sustainability, (2) project planning and control, (3) performance and effectiveness, (4) strategic management, (5) site and resource management, (6) risk analysis and management, (7) knowledge management, and (8) organization and stakeholder management. The analysis results reveal the pivotal role of SDM in streamlining different complicated casual relationships at the activity, project, and industry levels across the eight topics and its significant potential in uncovering the impact of complicated contextual conditions on project planning and control, effectiveness and performance, strategic management, and sustainability at the project and industry levels. Lastly, trends and recommendations for SDM applications are provided for future CM research. This paper provides a state of the art of SDM in CM applications and insights into opportunities and useful references for the future.

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