Cooperative Object Manipulation with Contact Impact Using Multiple Impedance Control

S. Ali A. Moosavian,Evangelos Papadopoulos 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.2

Impedance Control imposes a desired behavior on a single manipulator interacting with its environment. The Multiple Impedance Control (MIC) enforces a designated impedance on both a ma-nipulated object, and all cooperating manipulators. Similar to the standard impedance control, one of the benefits of this algorithm is the ability to perform both free motions and contact tasks without switching control modes. At the same time, the potentially large object inertia and other forces are taken into account. In this paper, the general formulation for the MIC algorithm is developed for dis-tinct cooperating manipulators, and important issues are detailed. Using a benchmark system, the re-sponse of the MIC algorithm is compared to that of the Object Impedance Control (OIC). It is shown that in the presence of flexibility, the MIC algorithm results in an improved performance. Next, a sys-tem of two cooperating two-link manipulators is simulated, in which a Remote Centre Compliance is attached to the second end-effector. As simulation results show, the response of the MIC algorithm is smooth, even in the presence of an impact due to collision with an obstacle. It is revealed by both error analysis and simulation that under the MIC law, all participating manipulators, and the manipulated object exhibit the same designated impedance behavior. This guarantees good tracking of manipulators and the object based on the chosen impedance laws which describe desired error dynamics, in performing a manipulation task.

Stable Gait Planning and Motion Control of Two Cooperative Humanoid Robots

S. Ali A. Moosavian,M. Hamid Ghazikhani,Alireza Janati 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

Control of the humanoid robots requires appropriate gait planning that satisfies stable walking. In this study, a Modified Transpose Jacobian (MTJ) control algorithm for object manipulation by two humanoid robots is developed. Such cooperative humanoid robots may typically get employed in hazardous situation and industrial applications. In the present paper, a high performance and robust controller was developed for the safe load handling, transportation and trajectory tracking. The MTJ algorithm, based on an approximated feedback linearization approach, employs stored data of the control command in the previous time step, to yield an improved performance. First, dynamic equations of the robot were derived. In order to verify the obtained dynamics equations, another model for the considered system has been developed using Matlab/SimMechanics simulation software. Comparison between the results obtained from these two dynamics models confirms the validity of the proposed analytical approach. Then, the stable walking gait based on ZMP approach was planned. Furthermore, the MTJ controller was applied to the robots and for comparison, the Transpose Jacobian (TJ) was also utilized. Significantly, it is shown that the MTJ yields smaller trajectory tracking errors than the TJ controller, without requiring high gains as TJ or extra computations as model-based algorithms which may not be feasible for on-line implementations.

Stabilization of a tractor-trailer wheeled robot

Ali Keymasi Khalaji,S. Ali A. Moosavian 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

Wheeled mobile robots are a special class of nonholonomic mechanical systems. The mobility of such highly nonlinear systems is restricteddue to the presence of nonholonomic constraints of wheels, also the system severe underactuated nature. These conditions generatemajor difficulties in system stabilization, i.e. to park or reach a given configuration for the overall system. This leads to a challengingcontrol problem for research that is the focus of this paper. In this paper a new method based on time-varying feedbacks has been developedfor a Tractor-trailer wheeled robot (TTWR). First kinematic model of the TTWR is obtained. Next, a novel method using timevaryingfeedbacks is investigated in order to stabilize the TTWR around the origin. The proposed kinematic control algorithm is developedbased on switching between two finite-time controllers. Appropriate control algorithms have been designed for each step based onthe stability of the closed loop system. Obtained simulation and experimental results show the effectiveness of the proposed control law.

Human model in the loop design optimization for RoboWalk wearable device

Mahdi Nabipour,S. Ali A. Moosavian 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

In this paper, a design optimization approach for assistive devices based on the simulation of the robot and human model is proposed. The proposed human model in the loop (HMIL) approach exploits an augmented human-robot model for interaction analysis, and to evaluate and modify the assistive device effectiveness. In this regard, a lower-limb assistive device (RoboWalk) for elderly and a human skeletal system are modeled and augmented to use the human-robot interaction forces in the proposed HMIL strategy. Due to the particular design of RoboWalk, a complete set of constraints are specified to ensure the solution feasibility and compatibility of the device in different poses. This constrained optimization problem is solved by weighted sum particle swarm optimization (WSPSO) and multi-objective PSO (MOPSO) algorithm. As a result of this optimization, several appropriate sets of design parameters are found to minimize the load on human joints, actuator torque and mass. Among the obtained optimal points, the point minimizing an introduced index is selected as the final design.

Dynamics and Stable Gait Planning of a Quadruped Robot

Ali Zamani,Mahdi Khorram,S. Ali A. Moosavian 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

In this paper, dynamics and gait planning of a quadruped robot is discussed. To this end, using Lagrangian method the equations of motion are first derived. Then, an approach is proposed to eliminate the terms corresponding to the constraints caused by the feet on the ground. The obtained dynamics model is validated using Matlab SimMechanics. Finally, gait planning of the robot is developed such that the robot can walk with a given speed over a flat terrain while the robot center of mass remains inside the support polygon. Obtained results reveal stable walking of a quadruped robot based on the proposed approach.

The Effect of Nutrition Education Program on Overweight/Obese Patients with Non-Alcoholic Fatty Liver Disease: a Single-Blind Parallel Randomized Controlled Trial

( Arman Arab ),( Amir Hadi ),( Seyedeh Parisa Moosavian ),( Nahid Rafie ),( Hossein Hajianfar ) 한국임상영양학회 2019 Clinical Nutrition Research Vol.8 No.3

The aim of this study was to assess the effects of a nutrition education program on overweight/obese patients with non-alcoholic fatty liver disease (NAFLD). This single-blind, parallel randomized controlled trial was conducted on 82 NAFLD patients (mean age 48.89 ± 9.85 years) in Isfahan, Iran. Patients were randomly allocated to receive nutrition education program combined with usual care or usual care alone for 2 months. Metabolic markers, including lipid profile, fasting blood glucose (FBG) and dietary intakes were obtained for each patient at baseline and at the end of the study. Nutrition education intervention resulted in a significant decrease compared with usual care in serum levels of total cholesterol (TC) and triglyceride (TG) (p < 0.05). However, our intervention did not lead to a significant improvement in FBG, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), respectively (p > 0.05). Furthermore, energy and sugar intakes of patients were reduced significantly in response to our intervention (p < 0.05). Nutrition education intervention significantly reduced serum levels of TC and TG but did not affect other metabolic markers including FBG, LDL-C, and HDL-C. Also, it could reduce total energy and sugar intake. Thus, this study could be useful to use this educational program for NAFLD patients in order to influence their metabolic markers and dietary intakes.

Modified transpose Jacobian control of a tractor-trailer wheeled robot

Ali Keymasi Khalaji,S. Ali A. Moosavian 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.9

Tractor-trailer wheeled robot (TTWR) is a modular robotic system that consists of a tractor module towing a trailer. Control of thesesystems started from motion aid facilities in human-driven vehicles, to fully autonomous mobile robots in recent years. The mobility ofsuch highly nonlinear systems is restricted due to the presence of nonholonomic constraints of wheels, also the system severe underactuatednature. Trajectory tracking is one of the challenging problems focused in the context of Wheeled mobile robots (WMRs) that hasbeen discussed in this paper. First, kinematic equations of TTWR are obtained. Then, reference trajectories for tracking problem are produced. Subsequently, a non-model-based controller based on Modified transpose jacobian (MTJ) method is designed to steer the TTWRasymptotically follow reference trajectories. Obtained simulation and experimental comparison results show the effectiveness of the proposedcontroller.

Vision-based formation control of aerial robots in the presence of sensor failure

Y. Abbasi,S. Ali A. Moosavian,Alireza B. Novinzadeh 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.3

This article presents vision-based formation flight control for aerial robots with a special focus on failure conditions in visual communication. Then, by proposing and combining two strategies, a new solution is presented for formation control. In vision-based formation flight, the state variables of the leader are estimated using image processing and unscented Kalman filter. The follower adjusts its position with respect to the leader based on the results of the estimation. In the case of visual communication failure an error will occur in the estimation of variables, which would increase with the decreased image quality. In the first proposed strategy, during the failure emergence, the position of the follower aerial robot is obtained by combining the unscented Kalman filter's estimated velocity vector and the velocity vector before failure. The weighting coefficient of each velocity vector is obtained by fuzzy logic and based on image quality. In the second strategy, to reduce the possibility of collision between the members, the geometry of the formation pattern is expanded as a function of image quality and the distance between the members. The expansion coefficient is also extracted by a fuzzy inference method, and the desired distance between the members is increased as a function of expansion coefficient. These two strategies are combined to be used during failure periods. Finally, simulation studies are presented which are conducted based on the system nonlinear equations, a model with 6 degrees of freedom for each member, and the proposed visual noise model. Obtained results reveal the proper capability of the proposed hybrid strategy in terms of controlling the formation flight during failure conditions.

Continuous biosorption of U(VI) and Fe(II) using Cystoseira indica biomass packed bed column: Breakthrough curves studies in single, binary and multi-component systems

Ali Reza Keshtkar,Ali Talebian,Mohammad Ali Moosavian 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.7

Ca-pretreated Cystoseira indica algae was used as a biosorbent for the biosorption of U(VI) and Fe(II) ions in single, binary and multi-component systems by using a packed bed column. Experiments were conducted to study the effect of important design parameters such as bed height and flow rate. FTIR and XRF analyses and pH and Ca2+ ion concentration recordings showed that the biosorption of U(VI) and Fe(II) proceeded through ion-exchange mechanism. BDST, Thomas and Modified dose-response models were used for predicting breakthrough curves and for estimations of the parameters necessary for the design of a large-scale packed bed column.

Stress, sensitivity and frequency analysis of the corrugated diaphragm for different corrugation structures

Meisam Farajollahi,Mehrad Goharzay,Daryoosh Borzuei,Seyed Farhan Moosavian 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.5

Corrugated and flat circular diaphragm-based piezoresistive pressure sensors are designed and proposed for different applications. Regarding to different criteria including maximum stress, sensitivity and natural frequency, different diaphragms with semicircular, sinusoidal and trapezoidal corrugation are modeled, simulated and investigated in finite element software. The finite element model is validated by experimental results from the literature and also with theoretical formula to ensure the accuracy of the finite element modeling process. Wavelength and location of the corrugation are optimized to achieve best performing sensor. For the application with large acceptable induced stress, circular flat diaphragm is proposed. To enhance the sensitivity of the sensor as a crucial parameter, semicircular corrugation for circular diaphragm with 360 <i>μ</i>mm wavelength and 240 <i>μ</i>mm distance from the center is designed and proposed. This configuration shows obvious improvement of the sensitivity with more than 18% enhancement. To extend the working range of the sensor regarding to input frequency, trapezoidal corrugation with 360 <i>μ</i>m wavelength and 240 <i>μ</i>mm distance from the center is proposed to reach more than 29% enlargement in first natural frequency. Eventually, this paper tries to provide an overview to design the optimal pressure sensor according to desired specifications.