Design and Hybrid Impedance Control of a Powered Rowing Machine

2017 ◽  
Author(s):  
Humberto de las Casas ◽  
Hanz Richter ◽  
Antonie van den Bogert
Keyword(s):  
Dynamic Model ◽  
Impedance Control ◽  
Force Sensor ◽  
Return Stroke ◽  
Control Approach ◽  
Return Spring ◽  
Force Velocity ◽  
Experimental Trials ◽  
Belt Transmission ◽  
And Control

A conventional rowing machine was modified with an electric motor and a robust impedance control system to mimic the behavior of a conventional rower and subsequently expand its versatility. The powered machine has programmable impedance and can produce controlled forces during the return stroke, allowing for eccentric exercise. Conventional rowers do not allow eccentric loading, an exercise modality known to contribute significantly to the efficacy of training. Eccentric loading is particularly important to diminish the detrimental effects of humans operating in microgravity for long periods of time. Conventional rowers include a flywheel, a fan and a freewheeling clutch. These elements were removed and replaced by a torque-controlled motor and a belt transmission selected on the basis of the forces and velocities encountered in the rowing exercise. A hybrid dynamic model was developed for the conventional rowing machine to account for its force-velocity characteristics and the transitions between the coupled (pull stroke) and the decoupled (return stroke) of the freewheeling clutch. Machine parameters such as flywheel inertia, air damping coefficients and return spring constants were identified from a set of experimental data and fitted to the model. The model was then used to design the robust hybrid impedance controller which includes a virtual flywheel and a force sensor to determine the transitions between pull and return strokes. The controller reproduces the operation of the original machine and can also be programmed to produce arbitrary impedances. The paper describes the hybrid dynamic model and control approach and the real-time experimental trials.

Modeling and control of a mobile manipulator

Robotica ◽  
1998 ◽  
Vol 16 (6) ◽  
pp. 607-613 ◽  
Author(s):  
J. H. Chung ◽  
S. A. Velinsky
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Harmful Effect ◽  
Euler Method ◽  
Friction Model ◽  
Mobile Manipulator ◽  
Wheel Slip ◽  
Modeling And Control ◽  
Control Approach ◽  
And Control

This paper concerns the modeling and control of a mobile manipulator which consists of a robotic arm mounted upon a mobile platform. The equations of motion are derived using the Lagrange-d'Alembert formulation for the nonholonomic model of the mobile manipulator. The dynamic model which considers slip of the platform's tires is developed using the Newton-Euler method and incorporates Dugoff's tire friction model. Then, the tracking problem is investigated by using a well known nonlinear control method for the nonholonomic model. The adverse effect of the wheel slip on the tracking of commanded motion is discussed in the simulation. For the dynamic model, a variable structure control approach is employed to minimize the harmful effect of the wheel slip on the tracking performance. The simulation results demonstrate the effectiveness of the proposed control algorithm.

Experimental validation on the integrated design and control of a parallel robot

Robotica ◽  
2005 ◽  
Vol 24 (2) ◽  
pp. 173-181 ◽  
Author(s):  
Qing Li
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Dynamic Models ◽  
Integrated Design ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Approximation Techniques ◽  
Control Approach ◽  
Modeling Errors ◽  
And Control

Due to the demands from the robotic industry, robot structures have evolved from serial to parallel. The control of parallel robots for high performance and high speed tasks has always been a challenge to control engineers. Following traditional control engineering approaches, it is possible to design advanced algorithms for parallel robot control. These approaches, however, may encounter problems such as heavy computational load and modeling errors, to name it a few. To avoid heavy computation, simplified dynamic models can be obtained by applying approximation techniques, nevertheless, performance accuracy will suffer due to modeling errors. This paper suggests applying an integrated design and control approach, i.e., the Design For Control (DFC) approach, to handle this problem. The underlying idea of the DFC approach can be illustrated as follows: Intuitively, a simple control algorithm can control a structure with a simple dynamic model quite well. Therefore, no matter how sophisticate a desired motion task is, if the mechanical structure is designed such that it results in a simple dynamic model, then, to design a controller for this system will not be a difficult issue. As such, complicated control design can be avoided, on-line computation load can be reduced and better control performance can be achieved. Through out the discussion in the paper, a 2 DOF parallel robot is redesigned based on the DFC concept in order to obtain a simpler dynamic model based on a mass-balancing method. Then a simple PD controller can drive the robot to achieve accurate point-to-point tracking tasks. Theoretical analysis has proven that the simple PD control can guarantee a stable system. Experimental results have successfully demonstrated the effectiveness of this integrated design and control approach.

Active Vibration Isolation for A Parallel Wheel-legged Robot Based on Dynamic Model

2020 ◽  
Author(s):  
Fei Guo ◽  
Shoukun Wang ◽  
Binkai Yue ◽  
Junzheng Wang
Keyword(s):  
Dynamic Model ◽  
Vibration Isolation ◽  
Force Feedback ◽  
Impedance Control ◽  
Inverse Kinematic ◽  
Control Input ◽  
Control Approach ◽  
Active Vibration ◽  
Robot Body ◽  
Active Vibration Isolation

Abstract Serving Stewart plat as wheel-legged construction, the most outstanding superiority of proposed wheel-legged hybrid robot (WLHR) is active vibration isolation during rolling on rugged terrain. This paper presents a force-driven control approach based on model predictive control (MPC) to design optimal control input for Stewart parallel wheel-leg that locomotes using swing foot trajectory. Adding adaptive impedance control in outermost loop, controlling framework prevents robot body horizontal and from vibration over rolling motion. Through dynamic model of Stewart mechanism, controller first creates predictive model by combining Newton-Euler equation, Newton-Raphson iteration of forward kinematic solving for current configuration, inverse kinematic calculation of Stewart obtaining desired joint position, and Gain/Integration module determining reference torque. With minimizing control deviation and input as objective function, a novel control optimization formulation generates optimum input for each control duration. These actuating force naturally enables each strut stretching and retracting used to realize six degree-of-freedom (6DOF) motion for Stewart wheel-leg. We exploit the variable-adapting method to reasonably adjust environmental impedance parameters by current position, velocity, force feedback of wheel-leg. This allow us to adequately acknowledge the desired support force tracking, isolating robot from isolation that is generated from unknown terrain. We demonstrate the validation of our control methodology on physical prototype by tracking a Bezier curve and active vibration isolation while the robot is rolling on decelerate strip. Respectively given PI controller and a sort of traditional impedance controller as comparison, a better performance of proposed algorithm was operated and evaluated through displacement and force sensors internally-installed in each cylinder, as well as IMU mounted on robot body.

Docking mechanism design and dynamic analysis for the GEO tumbling satellite

2019 ◽  
Vol 39 (3) ◽  
pp. 432-444
Author(s):  
Huang Jianbin ◽  
Li Zhi ◽  
Huang Longfei ◽  
Meng Bo ◽  
Han Xu ◽  
...  
Keyword(s):  
Mechanism Design ◽  
Dynamic Model ◽  
Control Method ◽  
Impact Force ◽  
Impedance Control ◽  
Active Force ◽  
Content Type ◽  
Control Approach ◽  
Docking Mechanism ◽  
The Impact

Purpose According to the requirements of servicing and deorbiting the failure satellites, especially the tumbling ones on geosynchronous orbit, this paper aims to design a docking mechanism to capture these tumbling satellites in orbit, to analyze the dynamics of the docking system and to develop a new collision force-limited control method in various docking speeds. Design/methodology/approach The mechanism includes a cone-rod mechanism which captures the apogee engine with a full consideration of despinning and damping characteristics and a locking and releasing mechanism which rigidly connects the international standard interface ring (Marman rings, such as 937B, 1194 and 1194A mechanical interface). The docking mechanism was designed under-actuated, aimed to greatly reduce the difficulty of control and ensure the continuity, synchronization and force uniformity under the process of repeatedly capturing, despinning, locking and releasing the tumbling satellite. The dynamic model of docking mechanism was established, and the impact force was analyzed in the docking process. Furthermore, a collision detection and compliance control method is proposed by using the active force-limited Cartesian impedance control and passive damping mechanism design. Findings A variety of conditions were set for the docking kinematics and dynamics simulation. The simulation and low-speed docking experiment results showed that the force translation in the docking phase was stable, the mechanism design scheme was reasonable and feasible and the proposed force-limited Cartesian impedance control could detect the collision and keep the external force within the desired value. Originality/value The paper presents a universal docking mechanism and force-limited Cartesian impedance control approach to capture the tumbling non-cooperative satellite. The docking mechanism was designed under-actuated to greatly reduce the difficulty of control and ensure the continuity, synchronization and force uniformity. The dynamic model of docking mechanism was established. The impact force was controlled within desired value by using a combination of active force-limited control approach and passive damping mechanism.

scholarly journals CAD DESIGN AND CONTROL OF TRIPLE INVERTED-PENDULUMS SYSTEM

2018 ◽  
Vol 18 (3) ◽  
pp. 481-497
Author(s):  
Mustafa T Hussein
Keyword(s):  
Dynamic Model ◽  
Lagrange Equation ◽  
Vertical Position ◽  
Cad Model ◽  
Nonlinear Dynamic Model ◽  
Pendulum System ◽  
Control Approach ◽  
Linearized Model ◽  
And Control ◽  
Future Work

This work is aimed to study the dynamic behavior and control of the triple invertedpendulumsystem. A nonlinear dynamic model of the inverted-pendulums fixed on a cart,based on CAD model is developed. The Lagrange equation is used to obtain the nonlineardynamic models of the system. The dynamic model is then linearized around operatingpoint. An augmented dynamic model using the linearized model is also derived. Two controlapproaches are used to stabilize the pendulums in vertical position. First approach: StateFeedback Control based on the linearized model is used to generate the input force control tostabilize the system. Second approach: Model Predictive Control is designed based onaugmented dynamic Model to control the motion of the system. In order to verify thedeveloped model and the chosen controller gains several simulations for different carts’paths are carried out. Several 3D animations are also presented to verify the usefulness ofthe designed CAD model and the controllers. As a future work: the 3D model of the tripleinverted-pendulum system gives a valuable resource for virtual reality work. Beside, anotheradvanced control approach can be applied on the derived dynamic model.

UNDERACTUATED HAND DYNAMIC MODELING, ITS REAL-TIME SIMULATION, AND CONTROL

2010 ◽  
Vol 07 (04) ◽  
pp. 609-634 ◽  
Author(s):  
HAI HUANG ◽  
YONG-JIE PANG ◽  
JIANG LI ◽  
SHAO-WEI FAN ◽  
XIN-QING WANG ◽  
...  
Keyword(s):  
Real Time ◽  
Dynamic Model ◽  
Dynamic Models ◽  
Impedance Control ◽  
Differential Algebraic Equations ◽  
Algebraic Equations ◽  
Inverse Dynamic ◽  
Time Dynamic ◽  
Simulation And Control ◽  
And Control

The forward and inverse dynamic models of the underactuated 2-DOF finger have been established in this article based on virtual spring approach. This approach not only avoids the solution of differential-algebraic equations but also leads to a completely decoupled dynamic model that is ideal for directly inverse dynamic analysis, real-time dynamic simulation and control. To verify this approach, an underactuated 3-joint finger has been brought forward. Simulation results from Matlab/Simulink are consistent with those obtained from ADAMS grasp simulations. For the hand real-time dynamic control, the velocity observer has been established based on the dynamic model, the adaptive curve fitting with the observer has obtained precise velocity signals, made up the uncertain parameters such as torsion spring, inertial, damps, etc. and achieved ideal results. By applying dynamics model and observer, the force-based impedance control can realize more accurate and stable force control during grasp.

scholarly journals Development, Modeling and Control of a Dual Tilt-Wing UAV in Vertical Flight

Drones ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 71
Author(s):  
Luz M. Sanchez-Rivera ◽  
Rogelio Lozano ◽  
Alfredo Arias-Montano
Keyword(s):  
Dynamic Model ◽  
Attitude Control ◽  
Test Bench ◽  
Aerodynamic Coefficients ◽  
Nonlinear Dynamic Model ◽  
Modeling And Control ◽  
Drag And Lift ◽  
And Control ◽  
Dynamics Method ◽  
Indoor And Outdoor

Hybrid Unmanned Aerial Vehicles (H-UAVs) are currently a very interesting field of research in the modern scientific community due to their ability to perform Vertical Take-Off and Landing (VTOL) and Conventional Take-Off and Landing (CTOL). This paper focuses on the Dual Tilt-wing UAV, a vehicle capable of performing both flight modes (VTOL and CTOL). The UAV complete dynamic model is obtained using the Newton–Euler formulation, which includes aerodynamic effects, as the drag and lift forces of the wings, which are a function of airstream generated by the rotors, the cruise speed, tilt-wing angle and angle of attack. The airstream velocity generated by the rotors is studied in a test bench. The projected area on the UAV wing that is affected by the airstream generated by the rotors is specified and 3D aerodynamic analysis is performed for this region. In addition, aerodynamic coefficients of the UAV in VTOL mode are calculated by using Computational Fluid Dynamics method (CFD) and are embedded into the nonlinear dynamic model. To validate the complete dynamic model, PD controllers are adopted for altitude and attitude control of the vehicle in VTOL mode, the controllers are simulated and implemented in the vehicle for indoor and outdoor flight experiments.

scholarly journals Sensorless environment stiffness and interaction force estimation for impedance control tuning in robotized interaction tasks

2021 ◽  
Author(s):  
Loris Roveda ◽  
Dario Piga
Keyword(s):  
Impedance Control ◽  
Interaction Force ◽  
Industrial Robots ◽  
Force Estimation ◽  
Interaction Control ◽  
Stiffness Properties ◽  
Implementation Effort ◽  
Coupling Dynamics ◽  
And Control ◽  
Assembly Tasks

AbstractIndustrial robots are increasingly used to perform tasks requiring an interaction with the surrounding environment (e.g., assembly tasks). Such environments are usually (partially) unknown to the robot, requiring the implemented controllers to suitably react to the established interaction. Standard controllers require force/torque measurements to close the loop. However, most of the industrial manipulators do not have embedded force/torque sensor(s) and such integration results in additional costs and implementation effort. To extend the use of compliant controllers to sensorless interaction control, a model-based methodology is presented in this paper. Relying on sensorless Cartesian impedance control, two Extended Kalman Filters (EKF) are proposed: an EKF for interaction force estimation and an EKF for environment stiffness estimation. Exploiting such estimations, a control architecture is proposed to implement a sensorless force loop (exploiting the provided estimated force) with adaptive Cartesian impedance control and coupling dynamics compensation (exploiting the provided estimated environment stiffness). The described approach has been validated in both simulations and experiments. A Franka EMIKA panda robot has been used. A probing task involving different materials (i.e., with different - unknown - stiffness properties) has been considered to show the capabilities of the developed EKFs (able to converge with limited errors) and control tuning (preserving stability). Additionally, a polishing-like task and an assembly task have been implemented to show the achieved performance of the proposed methodology.

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