Internet-Based Bilateral Teleoperation Based on Wave Variable With Semi-Adaptive Predictor and Direct Drift Control

2005 ◽  
Author(s):  
Ho Ching ◽  
Wayne J. Book
Keyword(s):  
Control Algorithm ◽  
Force Feedback ◽  
Transmission Delay ◽  
Bilateral Teleoperation ◽  
Robust Methods ◽  
Wave Variable ◽  
Rigid Contact ◽  
The Cost ◽  
Source Of Error ◽  
Drift Control

In a conventional bilateral teleoperation, transmission delay over the internet can potentially cause instability. One of the more robust methods of dealing with this problem is the wave variable. Wave variable guarantees teleoperation stability even under varying transmission delay at the cost of poor transient performance. Adding a predictor on the master side can reduce this undesirable side-effect, but that would require a slave model. Inaccurate slave model used in the predictor as well as variations in transmission delay, both of which are likely under realistic situations, can result in steady state errors. A direct drift control algorithm is used to drive this error to zero regardless of the source of error. A semi-adaptive predictor that can distinguish between free space and rigid contact environment is also used to provide a more accurate force feedback on the master side. This research presents the experimental results and evaluations of the previously mentioned wave variable based methods under realistic operation environment using real master and slave.

Internet-Based Bilateral Teleoperation Based on Wave Variable With Adaptive Predictor and Direct Drift Control

2005 ◽  
Vol 128 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Ho Ching ◽  
Wayne J. Book
Keyword(s):  
Force Feedback ◽  
Transmission Delay ◽  
Recursive Least Squares ◽  
Bilateral Teleoperation ◽  
Practical Applications ◽  
Wave Variable ◽  
Environmental Force ◽  
Rigid Contact ◽  
The Cost ◽  
Drift Control

In a conventional bilateral teleoperation, transmission delay over the Internet can potentially cause instability. A wave variable algorithm guarantees teleoperation stability under varying transmission delay at the cost of poor transient performance. Adding a predictor on the master side can reduce this undesirable side effect, but that would require a slave model. An inaccurate slave model used in the predictor as well as variations in transmission delay, both of which are likely under realistic situations, can result in steady-state errors. A direct drift control algorithm is used to drive this error to zero, regardless of the source of the error. A semi-adaptive predictor that can distinguish between free space and a rigid contact environment is used to provide a more accurate force feedback on the master side. A full adaptive predictor is also used that estimates the environmental force using recursive least squares with a forgetting factor. This research presents the experimental results and evaluations of the previously mentioned wave-variable-based methods under a realistic operation environment using a real master and slave. The algorithm proposed is innovative in that it takes advantage of the strengths of several control methods to build a promising bilateral teleoperation setup that can function under varying transmission delay, modeling error, and changing environment. Success could lead to practical applications in various fields, such as space-based remote control, and telesurgery.

Human Evaluation of Internet-Based Bilateral Teleoperation Using Wave Variables With Adaptive Predictor and Direct Drift Control

2006 ◽  
Author(s):  
Ho Ching ◽  
Wayne J. Book
Keyword(s):  
Human Subjects ◽  
Transmission Delay ◽  
Bilateral Teleoperation ◽  
Wave Variables ◽  
Human Evaluation ◽  
Maze Navigation ◽  
Improved Performance ◽  
Tracking Surface ◽  
The Cost ◽  
Drift Control

In a conventional bilateral teleoperation, transmission delay over the Internet can potentially cause instability. The wave variables algorithm can solve this problem at the cost of poor transient response. The wave variables algorithm with adaptive predictor and drift control based on our previous work [24] has been proposed to provide stability under time delay with improved performance. The effectiveness of this algorithm is fully evaluated using human subjects with no previous experience in haptics. Three algorithms are tested using Phantom haptic devices as master and slave: conventional bilateral teleoperation with no transmission delay as control, wave variables with 200-300 ms transmission delay one way, and wave variables with adaptive predictor and direct drift control (WAPD) also with 200-300 ms delay one way. For each algorithm the human subjects are asked to perform three simple tasks: free space trajectory tracking, surface contour identification, and maze navigation. The results show WAPD to be superior to regular wave variables algorithm with higher subject ratings.

Wave-Variable Based Force Feedback for a Space-Qualified Telerobot

2008 ◽  
Author(s):  
J. Scot Hart ◽  
Pete Shull ◽  
Diana Gentry ◽  
Gu¨nter Niemeyer ◽  
Stephen Roderick ◽  
...  
Keyword(s):  
Dynamic Capabilities ◽  
Force Feedback ◽  
Contact Forces ◽  
Stable Operation ◽  
Bilateral Teleoperation ◽  
Large Space ◽  
Wave Variable ◽  
Control Framework ◽  
Acceleration Feedback ◽  
Local Feedback

Bilateral teleoperation across significant time delays has been extensively studied and is posed to provide remote control of orbiting robots. Unfortunately, most standard approaches assume an impedance controlled, backdrivable robot. In this work, we apply wave variable control to Ranger, a large, space-qualified, geared robot. We incorporate local feedback of contact forces into the control framework to achieve backdrivable operation. In particular, this control framework imitates an idealized point mass to respect Ranger’s dynamic capabilities. Beyond perceiving steady state contact forces, the user’s perception can be enhanced with high-frequency acceleration feedback of contact transients. Experimental results from controlling Ranger using network communications show stable operation in free space and contact.

scholarly journals Intelligent Routing Control for MANET Based on Reinforcement Learning

2018 ◽  
Vol 232 ◽  
pp. 04002
Author(s):  
Fang Dong ◽  
Ou Li ◽  
Min Tong
Keyword(s):  
Reinforcement Learning ◽  
Control Algorithm ◽  
Rapid Development ◽  
Selection Strategy ◽  
Performance Simulation ◽  
Multiple Parameters ◽  
Intelligent Routing ◽  
Routing Control ◽  
The Cost

With the rapid development and wide use of MANET, the quality of service for various businesses is much higher than before. Aiming at the adaptive routing control with multiple parameters for universal scenes, we propose an intelligent routing control algorithm for MANET based on reinforcement learning, which can constantly optimize the node selection strategy through the interaction with the environment and converge to the optimal transmission paths gradually. There is no need to update the network state frequently, which can save the cost of routing maintenance while improving the transmission performance. Simulation results show that, compared with other algorithms, the proposed approach can choose appropriate paths under constraint conditions, and can obtain better optimization objective.

scholarly journals Fuzzy Control and Connected Region Marking Algorithm-Based SEM Nanomanipulation

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Dongjie Li ◽  
Weibin Rong ◽  
Lining Sun ◽  
Bo You ◽  
Yu Zou ◽  
...  
Keyword(s):  
Fuzzy Control ◽  
Control Algorithm ◽  
Force Feedback ◽  
Connected Region ◽  
Feedback Information ◽  
Sem Image ◽  
Position Data ◽  
Update Rate ◽  
Fuzzy Control Algorithm ◽  
Slave Mode

The interactive nanomanipulation platform is established based on fuzzy control and connected region marking (CRM) algorithm in SEM. The 3D virtual nanomanipulation model is developed to make up the insufficiency of the 2D SEM image information, which provides the operator with depth and real-time visual feedback information to guide the manipulation. The haptic device Omega3 is used as the master to control the 3D motion of the nanopositioner in master-slave mode and offer the force sensing to the operator controlled with fuzzy control algorithm. Aiming at sensing of force feedback during the nanomanipulation, the collision detection method of the virtual nanomanipulation model and the force rending model are studied to realize the force feedback of nanomanipulation. The CRM algorithm is introduced to process the SEM image which provides effective position data of the objects for updating the virtual environment (VE), and relevant issues such as calibration and update rate of VE are also discussed. Finally, the performance of the platform is validated by the ZnO nanowire manipulation experiments.

Transparent four-channel bilateral control architecture using modified wave variable controllers under time delays

Robotica ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 859-875 ◽  
Author(s):  
Da Sun ◽  
Fazel Naghdy ◽  
Haiping Du
Keyword(s):  
Time Delays ◽  
Large Time ◽  
Wave Transformation ◽  
Bilateral Teleoperation ◽  
Bilateral Control ◽  
Wave Variable ◽  
Guarantee System ◽  
Remote Environment ◽  
The Stability ◽  
Teleoperation Systems

SUMMARYStability and transparency are two critical indices of bilateral teleoperation systems. The wave variable method is a conservative approach to robustly guarantee system passivity under arbitrary constant time delays. However, the wave-variable-based reflection is an intrinsic problem in this method because it can significantly degrade system transparency and disorient the operator's perception of the remote environment. In order to enhance both the transparency and the stability of bilateral teleoperation systems in the presence of large time delays, a new four-channel (4-CH) architecture is proposed which applies two modified wave-transformation controllers to reduce wave-based reflections. Transparency and stability of the proposed system are analyzed and the improvement in these when using this method is measured experimentally. Results clearly demonstrate that the proposed method can produce high transparency and stability even in the presence of large time delays.

The Development of a Human Gait Model With Predictive Capability and the Simulation of Able-Bodied Gait

2015 ◽  
Author(s):  
Jinming Sun ◽  
Shaoli Wu ◽  
Philip A. Voglewede
Keyword(s):  
Control Algorithm ◽  
Human Subjects ◽  
Human Gait ◽  
Control Input ◽  
Trial And Error ◽  
Predictive Capability ◽  
Gait Simulation ◽  
Plant Model ◽  
The Central Nervous System ◽  
The Cost

The development of current prostheses and orthoses typically follows a trial and error approach where the devices are designed based on experience, tried on human subjects and then redesigned iteratively. This design approach is costly, risky and time consuming. A predictive human gait model is desired such that prostheses can be virtually tested so that their performance can be predicted qualitatively, the cost can be reduced, and the risks can be minimized. The development of such a model is explained in this paper. The developed model includes two parts: a plant model which represents the forward dynamics of human gait and a controller which represents the central nervous system (CNS). The development of the plant model is explained in a different paper. This paper focuses on the control algorithm development and able-bodied gait simulation. The controller proposed in this paper utilizes model predictive control (MPC). MPC uses an internal model to predict the output in advance, compare the predicted output to the reference, and optimize control input so that the error between them is minimal. The developed predictive human gait model was validated by simulating able-bodied human gait. The simulation results showed that the controller is able to simulate the kinematic output close to experimental data.

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