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.

Decentralized Exergy/Entropy Thermodynamic Control for Collective Robotic Systems

2007 ◽  
Author(s):  
Rush D. Robinett ◽  
David G. Wilson
Keyword(s):  
Decentralized Control ◽  
Direct Method ◽  
Robotic Systems ◽  
Control Law ◽  
Thermodynamic Control ◽  
Order Accuracy ◽  
Control Laws ◽  
Vector Lyapunov Function ◽  
Collective Control ◽  
Plume Tracing

This paper develops a distributed decentralized control law for collective robotic systems. The control laws are developed based on exergy/entropy thermodynamic concepts and information theory. The source field is characterized through second-order accuracy. The proposed feedback control law stability for both the collective and individual robots are demonstrated by selecting a general Hamiltonian based solution developed as Fisher Information Equivalency as the vector Lyapunov function. Stability boundaries and system performance are then determined with Lyapunov’s direct method. A robot collective plume tracing numerical simulation example demonstrates this decentralized exergy/entropy collective control architecture.

scholarly journals Smart and Modular

2011 ◽  
Vol 133 (09) ◽  
pp. 48-51
Author(s):  
Harry H. Cheng ◽  
Graham Ryland ◽  
David Ko ◽  
Kevin Gucwa ◽  
Stephen Nestinger
Keyword(s):  
Degrees Of Freedom ◽  
Robotic System ◽  
Search And Rescue ◽  
Degree Of Freedom ◽  
Robotic Systems ◽  
Modular Robots ◽  
Modular Robot ◽  
Modular Systems ◽  
The Past ◽  
Three Degrees Of Freedom

This article discusses the advantages of a modular robot that can reassemble itself for different tasks. Modular robots are composed of multiple, linked modules. Although individual modules can move on their own, the greatest advantage of modular systems is their structural reconfigurability. Modules can be combined and assembled to form configurations for specific tasks and then reassembled to suit other tasks. Modular robotic systems are also very well suited for dynamic and unpredictable application areas such as search and rescue operations. Modular robots can be reconfigured to suit various situations. Quite a number of modular robotic system prototypes have been developed and studied in the past, each containing unique geometries and capabilities. In some systems, a module only has one degree of freedom. In order to exhibit practical functionality, multiple interconnected modules are required. Other modular robotic systems use more complicated modules with two or three degrees of freedom. However, in most of these systems, a single module is incapable of certain fundamental locomotive behaviors, such as turning.

Actuator Array Dynamics Incorporating Actuator Inertia

2013 ◽  
Author(s):  
Mark D. Bedillion
Keyword(s):  
Degrees Of Freedom ◽  
Friction Model ◽  
Object Motion ◽  
Prior Work ◽  
Control Laws ◽  
Distributed Manipulation ◽  
Actuator Arrays ◽  
Simulation Results ◽  
Two Degree Of Freedom ◽  
Three Degrees Of Freedom

Actuator arrays are planar distributed manipulation systems that use multiple two degree-of-freedom actuators to manipulate objects with three degrees of freedom (x, y, and θ). Prior work has discussed actuator array dynamics while neglecting the inertia of the actuators; this paper extends prior work to the case of non-negligible actuator inertia. The dynamics are presented using a standard friction model incorporating stiction. Simulation results are presented that show object motion under previously derived control laws.

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.

A multi-configuration kinematic model for active drive/steer four-wheel robot structures

Robotica ◽  
2015 ◽  
Vol 34 (10) ◽  
pp. 2309-2329 ◽  
Author(s):  
Edgar A. Martínez-García ◽  
Erik Lerín-García ◽  
Rafael Torres-Córdoba
Keyword(s):  
Degrees Of Freedom ◽  
Rotation Axis ◽  
Contact Point ◽  
Linear Equations ◽  
Kinematic Model ◽  
Robotic Systems ◽  
Control Law ◽  
Special Design ◽  
Wheel Drive ◽  
Four Wheel Drive

SUMMARYIn this study, a general kinematic control law for automatic multi-configuration of four-wheel active drive/steer robots is proposed. This work presents models of four-wheel drive and steer (4WD4S) robotic systems with all-wheel active drive and steer simultaneously. This kinematic model comprises 12 degrees of freedom (DOFs) in a special design of a mechanical structure for each wheel. The control variables are wheel yaw, wheel roll, and suspension pitch by active/passive damper systems. The pitch angle implies that a wheel's contact point translates its position over time collinear with the robot's lateral sides. The formulation proposed involves the inference of the virtual z-turn axis (robot's body rotation axis) to be used in the control of the robot's posture by at least two acceleration measurements local to the robot's body. The z-turn axis is deduced through a set of linear equations in which the number of equations is equal to the number of acceleration measurements. This research provides two main models for stability conditions. Finally, the results are sustained by different numerical simulations that validate the system with different locomotion configurations.

Analysis and simulation of a new Cartesian cable-suspended robot

2009 ◽  
Vol 224 (8) ◽  
pp. 1717-1726 ◽  
Author(s):  
G Castelli ◽  
E Ottaviano ◽  
A González
Keyword(s):  
Numerical Simulation ◽  
Degrees Of Freedom ◽  
Robot Arm ◽  
Fixed Frame ◽  
Cartesian Space ◽  
Compliant Assembly ◽  
Moving Platform ◽  
Geometry Analysis ◽  
Three Degrees Of Freedom

In this article, a manipulator is presented belonging to the class of cable-suspended robots, for which the cable length variations are related by suitable functions in order to achieve specific kinematic characteristics. In particular, in this article, a Cartesian cable-suspended robot is proposed that has eight cables to have three degrees of freedom (DOF) in Cartesian space. The eight cables of the robot are arranged in parallel by pairs with identical length, with the aim of constraining the moving platform to keep a constant orientation with respect to the fixed frame. The robot can be used for selective compliant assembly robot arm (SCARA) motions (when an additional revolute actuated joint is placed on the moving platform) for a variety of applications in which a large workspace is required. In this article, a geometry analysis of the robot is presented together with a numerical simulation of the kinetostatics and dynamics to investigate the robot's performances in several operative conditions. Furthermore, a characterization of the position workspace regions is reported for this cable-suspended robot.

Model-Based Control of Three Degrees of Freedom Robotic Bulldozing

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Scott G. Olsen ◽  
Gary M. Bone
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Removal Rate ◽  
Optimal Controller ◽  
Control Laws ◽  
Rule Based ◽  
Three Degrees Of Freedom

This brief paper investigates the control of a robotic bulldozing operation. Optimal blade position control laws were designed based on a hybrid dynamic model to maximize the predicted material removal rate of the bulldozing process. Experiments were conducted with a scaled-down robotic bulldozing system. The control laws were implemented with various tuning values. As a comparison, a rule-based blade control algorithm was also designed and implemented. The experimental results with the best optimal controller demonstrated a 33% increase in the average material removal rate compared to the rule-based controller.

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.

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