Discussion On “Selective-Compliance-Based Lagrange Model and Multilevel Non-Collocated Feedback Control of a Humanoid Robot”

2020 ◽  
pp. 1-7
Author(s):  
Gustavo A. Medrano-Cerda
Keyword(s):  
Feedback Control ◽  
State Feedback ◽  
Humanoid Robot ◽  
Velocity Feedback ◽  
Technical Errors ◽  
Full State ◽  
Full State Feedback ◽  
The Stability ◽  
Motor Velocity ◽  
Stability Results

Abstract The publication [1] makes unjustified claims, has many inconsistencies, numerous technical errors in the theoretical exposition and omitted proofs. The stability claim of the COM dynamics is incomplete and errors increase in time indicating that the robot is unstable and will eventually fall. The range of disturbances that the controller can handle is not suitably addressed. In addition the reported tracking stability results, for PDD control (motor position, motor velocity and link velocity feedback) and PPDD (full state feedback), have already been published by Lanari [1a], [2a] for a larger class of models and with full details of the corresponding Lagrange stability proofs.

scholarly journals Stability Analysis of an Inverted Pendulum on a Cart with the Presence of Restoring and Frictional Forces Disturbance using Observer Based and Full State Feedback H2 Controllers

2020 ◽  
Author(s):  
Mustefa Jibril ◽  
Messay Tadese ◽  
Fiseha Bogale
Keyword(s):  
State Feedback ◽  
Inverted Pendulum ◽  
Stability Control ◽  
System Stability ◽  
Lagrangian Equation ◽  
System Equation ◽  
Full State ◽  
Full State Feedback ◽  
Frictional Forces ◽  
The Stability

In this paper, the stability control of the inverted pendulum on a cart with a disturbance forces has been done using observer based and full state feedback H2 controllers. The Lagrangian equation has been used to model the system equation of motions and linearized the system to the unstable upward position. Comparison of the system stability has been simulated by comparing the proposed controllers using Matlab/Scripts and a promising results has been analyzed successfully.

scholarly journals Frequency-Adaptive Current Controller Design Based on LQR State Feedback Control for a Grid-Connected Inverter under Distorted Grid

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2674 ◽  
Author(s):  
Rizka Bimarta ◽  
Thuy Vi Tran ◽  
Kyeong-Hwa Kim
Keyword(s):  
Feedback Control ◽  
Discrete Time ◽  
State Feedback ◽  
State Feedback Control ◽  
Frequency Variation ◽  
Grid Voltage ◽  
Frequency Information ◽  
Full State ◽  
Full State Feedback ◽  
Grid Connected Inverter

This paper proposes a frequency-adaptive current control design for a grid-connected inverter with an inductive–capacitive–inductive (LCL) filter to overcome the issues relating to both the harmonic distortion and frequency variation in the grid voltage. The current control scheme consists of full-state feedback control to stabilize the system and integral control terms to track the reference in the presence of disturbance and uncertainty. In addition, the current controller is augmented with resonant control terms to mitigate the harmonic component. The control scheme is implemented in the synchronous reference frame (SRF) to effectively compensate two harmonic orders at the same time by using only one resonant term. Moreover, to tackle the frequency variation issue in grid voltage, the frequency information which is extracted from the phase-locked loop (PLL) block is processed by a moving average filter (MAF) for the purpose of eliminating the frequency fluctuation caused by the harmonically distorted grid voltage. The filtered frequency information is employed to synthesize the resonant controller, even in the environment of frequency variation. To implement full-state feedback control for a grid-connected inverter with an LCL filter, all the state variables should be available. However, the increase in number of sensing devices leads to the rise of cost and complexity for hardware implementation. To overcome this challenge, a discrete-time full-state current observer is introduced to estimate all the system states. When the grid frequency is subject to variation, the discrete-time implementation of the observer in the SRF requires an online discretization process because the system matrix in the SRF includes frequency information. This results in a heavy computational burden for the controller. To resolve such a difficulty, a discrete-time observer in the stationary reference frame is employed in the proposed scheme. In the stationary frame, the discretization of the system model can be accomplished with a simple offline method even in the presence of frequency variation since the system matrix does not include the frequency. To select desirable gains for the full-state feedback controller and full-state observer, an optimal linear quadratic control approach is applied. To validate the practical effectiveness of the proposed frequency-adaptive control, simulation and experimental results are presented.

scholarly journals Full-State Feedback Control Design for Shape Formation using Linear Quadratic Regulator

2020 ◽  
Vol 2 (2) ◽  
pp. 83
Author(s):  
Muhamad Rausyan Fikri ◽  
Djati Wibowo Djamari
Keyword(s):  
Feedback Control ◽  
State Feedback ◽  
Linear Quadratic Regulator ◽  
State Feedback Control ◽  
Linear Quadratic ◽  
Shape Formation ◽  
Full State ◽  
Full State Feedback ◽  
Input Response ◽  
Agent Coordination

This study investigated the capability of a group of agents to form a desired shape formation by designing the feedback control using a linear quadratic regulator. In real application, the state condition of agents may change due to some particular problems such as a slow input response. In order to compensate for the problem that affects agent-to-agent coordination, a robust regulator was implemented into the formation algorithm. In this study, a linear quadratic regulator as the full-state feedback of robust regulator method for shape formation was considered. The result showed that a group of agents can form the desired shape (square) formation with a modification of the trajectory shape of each agent. The results were validated through numerical experiments.

scholarly journals Stability Control of Double Inverted Pendulum on a Cart Using Full State Feedback with H infinity and H 2 Controllers

2020 ◽  
Author(s):  
Mustefa Jibril ◽  
Messay Tadese ◽  
Reta Degefa
Keyword(s):  
Feedback Control ◽  
State Feedback ◽  
Inverted Pendulum ◽  
Stability Control ◽  
State Feedback Control ◽  
Superior Performance ◽  
Lagrange Equations ◽  
H Infinity ◽  
Full State ◽  
Full State Feedback

In this paper a full state feedback control of a double inverted pendulum on a cart (DIPC) are designed and compared. Modeling is based on Euler-Lagrange equations derived by specifying a Lagrangian, difference between kinetic and potential energy of the DIPC system. A full state feedback control with H infinity and H 2 is addressed. Two approaches are tested: open loop impulse response and a double inverted pendulum on a cart with full state feedback H infinity and H 2 controllers. Simulations reveal superior performance of the double inverted pendulum on a cart with full state feedback H infinity controller.

scholarly journals Stability Control of Double Inverted Pendulum on a Cart using Full State Feedback with H infinity and H 2 Controllers

2020 ◽  
Author(s):  
Mustefa Jibril ◽  
Messay Tadese ◽  
Reta Degefa
Keyword(s):  
Feedback Control ◽  
State Feedback ◽  
Inverted Pendulum ◽  
Stability Control ◽  
State Feedback Control ◽  
Superior Performance ◽  
Lagrange Equations ◽  
H Infinity ◽  
Full State ◽  
Full State Feedback

In this paper a full state feedback control of a double inverted pendulum on a cart (DIPC) are designed and compared. Modeling is based on Euler-Lagrange equations derived by specifying a Lagrangian, difference between kinetic and potential energy of the DIPC system. A full state feedback control with H infinity and H 2 is addressed. Two approaches are tested: open loop impulse response and a double inverted pendulum on a cart with full state feedback H infinity and H 2 controllers. Simulations reveal superior performance of the double inverted pendulum on a cart with full state feedback H infinity controller.

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