A New Methodology for Robot Controller Design

2005 ◽  
Author(s):  
Jan Peters ◽  
Michael Mistry ◽  
Firdaus Udwadia ◽  
Stefan Schaal
Keyword(s):  
Controller Design ◽  
Nonholonomic Constraints ◽  
Rigid Body Dynamics ◽  
Specific Class ◽  
Open Chain ◽  
Control Laws ◽  
Suggested Approach ◽  
Robot Controller ◽  
Closed Chain ◽  
Gauss Principle

Gauss’ principle of least constraint and its generalizations have provided a useful insights for the development of tracking controllers for mechanical systems [1]. Using this concept, we present a novel methodology for the design of a specific class of robot controllers. With our new framework, we demonstrate that well-known and also several novel nonlinear robot control laws can be derived from this generic framework, and show experimental verifications on a Sarcos Master Arm robot for some of these controllers. We believe that the suggested approach unifies and simplifies the design of optimal nonlinear control laws for robots obeying rigid body dynamics equations, both with or without external constraints, holonomic or nonholonomic constraints, with over-actuation or underactuation, as well as open-chain and closed-chain kinematics.

scholarly journals Evaluation of Ankle Mobility Loss in Patients Undergoing Subtalar Arthrodesis

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0011
Author(s):  
Tiago S. Baumfeld ◽  
Roberto Zambelli de A. Pinto ◽  
Fernando Araujo S. Lopes ◽  
Daniel Baumfeld ◽  
Camilo Tavares
Keyword(s):  
Range Of Motion ◽  
Plantar Flexion ◽  
Contralateral Side ◽  
Foot And Ankle ◽  
Lower Range ◽  
Open Chain ◽  
Subtalar Arthrodesis ◽  
Closed Chain ◽  
Ankle Mobility ◽  
Dorsal Flexion

Category: Hindfoot Introduction/Purpose: Objective: To evaluate and quantify the loss of ankle mobility in patients undergoing subtalar arthrodesis compared to the contralateral side, through physical examination. Methods: A total of 12 patients who had only the subtalar arthrodesis procedure from various causes in one foot were selected. The same foot and ankle surgeon performed all measurements of bilateral tibiotarsal range of motion, with loaded closed-chain and unloaded open-chain tests. Then, to assess whether there was a difference between the operated and the non-operated side, statistical analysis was performed with the Mann-Whitney test (Hollander and Wolfe 1999). Results: On the loaded closed-chain test, the operated side had a significantly lower range of motion than the contralateral side, with a mean difference of 5.4 degrees for dorsal flexion and 7.6 degrees for plantar flexion. The open-chain tests showed non- significant differences of 3 degrees for dorsal flexion and 5.3 degrees for plantar flexion. Conclusion: Subtalar joint arthrodesis was shown to cause a loss of mobility in the ipsilateral ankle, which is greater in plantar flexion movement.

Simulation of a dynamic vertical jump

Robotica ◽  
2001 ◽  
Vol 19 (1) ◽  
pp. 87-91 ◽  
Author(s):  
M. Guihard ◽  
P. Gorce
Keyword(s):  
Controller Design ◽  
Vertical Jump ◽  
Rigid Bodies ◽  
Pneumatic Actuator ◽  
Dynamic Effects ◽  
Complex Motion ◽  
Control Laws ◽  
Dynamic Tracking ◽  
High Acceleration ◽  
Mechanical Models

The aim of this paper is to propose a bipedal structure able to follow high acceleration movements. The vertical jump of a human has been chosen as input (coming from experiments) to validate the controller design as it is one of the most complex motion. The study concerns the low level of the biped control that is to say the control design of one leg made of three rigid bodies, each of them moved by a pneumatic actuator. An analogy between a pneumatic actuator and a physiological muscle is first proposed. A dynamic model of the leg is then presented decoupling the dynamic effects of the skeletal (as interactions between segments) from the dynamic effects of the muscles involved. The controller is based on the nonlinear theory (taking into account the actuator and the mechanical models), it ensures a dynamic tracking of position and force. Its originality lays in the consideration of impedance behaviour at each joint during free and constrained tasks. It leads to asymptotically stable (Popov criteria) control laws which are continuous between contact and non-contact phases enabling real-time computations. The simulation results clearly show the tracking of position and forces during the whole jump cycle.

scholarly journals Easy Tracking of UAV Using PID Controller

2018 ◽  
Vol 47 (3) ◽  
pp. 171-177 ◽  
Author(s):  
Satla Zouaoui ◽  
Elajrami Mohamed ◽  
Bendine Kouider
Keyword(s):  
Pid Controller ◽  
Controller Design ◽  
Rigid Body Dynamics ◽  
Simulation Studies ◽  
Simple Strategy ◽  
Matlab Program ◽  
Fluid Velocities ◽  
Body Dynamics ◽  
Pid Controller Design ◽  
Surrounding Fluid

The main objective of the present paper is to design a mathematical model to estimate the behavior of flying robots with four motors (quadcopters) controlled by three algorithms; P depends on the present errors; I on the accumulation of past errors, and D a prediction of future errors (PID controller design) with simple strategy. In this regard, a governing equation of motion based on Newton Euler’s formularies for rigid body dynamics is presented. In order to design the control algorithm some assumptions are made such as the ignorance of the blade flapping, surrounding fluid velocities. This exclusion of parameters makes the model flexible, simple, and allows the control to be more efficiency and easy to designed without the need of expensive computation. The simulation studies are carried out using MATLAB program.

scholarly journals Spectra of Local Cluster Flows on Open Chain of Contours

2018 ◽  
Vol 11 (3) ◽  
pp. 628-644 ◽  
Author(s):  
Alexander Pavlovich Buslaev ◽  
Alexander G Tatashev
Keyword(s):  
Dynamical System ◽  
Unit Length ◽  
Self Organization ◽  
Similar System ◽  
Open Chain ◽  
Local Cluster ◽  
Closed Chain

A dynamical system is considered. This dynamical system is a flow of clusters with the same length $l$ on contours of unit length connected into open chain. A similar system such that contours of this system are connected into closed chain was considered earlier. It has been found that, in the case of closed chain of contours, the dynamical system has a spectrum of velocity and mode periodicity consisted of more than one component. In this paper, it has been shown that, in the case of open chain, the spectrum of cluster velocity and mode periodicity contains only one component.The conditions of self-organization and the dependence of cluster velocity on load $l$ is developed.

EXACT GROUND STATES OF ONE-DIMENSIONAL VALENCE-BOND-SOLID HAMILTONIANS

1987 ◽  
Vol 01 (05n06) ◽  
pp. 231-237 ◽  
Author(s):  
P.L. Iske ◽  
W.J. Caspers
Keyword(s):  
Ground State ◽  
Valence Bond ◽  
Ground States ◽  
Open Chain ◽  
State Correlation ◽  
One Dimensional ◽  
Degenerate Ground State ◽  
Closed Chain ◽  
Ground State Correlation ◽  
Valence Bond Solid

The ground state(s) of a Hamiltonian, introduced by Affleck, Kennedy, Lieb and Tasaki, in connection with the Valence-Bond-Solid (VBS) states, are explicitly given for the spin-1 chains. The structure of these ground states is a rather simple one. For a closed chain we find a unique ground state; for the open chain we find a fourfold-degenerate ground state. The ground state correlation function for the ring is calculated.

Fuzzy Feedback Control for Real-Time Dynamic Traffic Routing: User Equilibrium Model Formulations and Controller Design

1996 ◽  
Vol 1556 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Pushkin Kachroo ◽  
Kaan Özbay
Keyword(s):  
Feedback Control ◽  
Real Time ◽  
Controller Design ◽  
User Equilibrium ◽  
System Dynamics Model ◽  
Dynamics Model ◽  
Dynamic Traffic ◽  
Control Laws ◽  
Time Dynamic ◽  
Traffic Routing

The formulation of a system dynamics model for the dynamic traffic routing (DTR) problem is addressed, specifically for the application of real-time feedback control. Also addressed is the design of fuzzy feedback control laws for this problem. Fuzzy feedback control is suitable for solving the DTR problem, which is nonlinear and time varying and contains uncertainties. To illustrate the applicability of fuzzy logic in the design of feedback control for DTR, a simple software simulation was conducted that provided encouraging results.

Design, iterative synthesis and structure of novel optically active trispiro-dendritic melamines incorporating ‘open-chain’ versus ‘closed-chain’ serinolic peripheral units

2015 ◽  
Vol 26 (14) ◽  
pp. 683-701 ◽  
Author(s):  
Oana Moldovan ◽  
Iulia Nagy ◽  
Pedro Lameiras ◽  
Cyril Antheaume ◽  
Carmen Sacalis ◽  
...  
Keyword(s):  
Optically Active ◽  
Open Chain ◽  
Closed Chain ◽  
Iterative Synthesis

Local joint control in cooperating manipulator systems - force distribution and global stability

Robotica ◽  
1993 ◽  
Vol 11 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Greg R. Luecke ◽  
John F. Gardner
Keyword(s):  
Industrial Robot ◽  
Kinematic Chain ◽  
Joint Control ◽  
Constrained Motion ◽  
Computationally Efficient ◽  
Open Chain ◽  
Control Laws ◽  
Kinematic Chains ◽  
Computationally Intensive ◽  
Control Forces

SUMMARYAlmost all industrial robot applications in use today are controlled using a control law that is simple and computationally efficient, local joint error feedback. When two or more open chain manipulators cooperate to manipulate the same object - such as in mechanical grippers, walking machines, and cooperating manipulator systems - closed kinematic chain, redundantly actuated mechanisms are formed. Control approaches for this type of system focus on the more computationally intensive computed torque or inverse plant control laws, due to the concern over instability caused by the unspecified distribution of control forces in the redundant actuator space, and due to the constrained motion caused by the closed kinematic chains.

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