A Robust Control Concept for Robotic Ankle Gait Assistance

Hollander, Kevin W.; Sugar, Thomas G.

doi:10.1109/icorr.2007.4428416

Cited by 14 publications

(14 citation statements)

References 12 publications

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“…Firstly, since clear and simply detectable transition signals were used, the controller was able to switch through the states continuously without getting locked into one state. Secondly, the motor and lever curves that have been obtained during the test are similar to the ones that are obtained through simulation in [8], which verifies the models. Thirdly, no predefined nut pattern was used to obtain the The robot is interacting with the user rather than forcing the user into its pattern.…”

Section: Discussionmentioning

confidence: 95%

“…9. Ankle Angle Divided Into Zones for One Gait Cycle [8] force, is used as well to zero the robot. In order to detect the transitions between the zones, a heel and toe switch is needed.…”

Section: Methodsmentioning

confidence: 99%

“…The theoretical foundation for a very promising new method has been developed by Sugar and Hollander [7], [8]. Their approach is a mixture between stiffness control and velocity control.…”

Section: The Robust Control Conceptmentioning

confidence: 99%

“…In [8], Hollander suggests to split up the stance phase of gait into five distinct zones, see Fig. 9, whereas each zone will be governed by a certain control law, either velocity control or stiffness control.…”

Section: B Combination Of Velocity and Stiffness Controlmentioning

confidence: 99%

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Design, implementation and test results of a robust control method for a powered ankle foot orthosis (AFO)

Boehler

Hollander²,

Sugar

et al. 2008

2008 IEEE International Conference on Robotics and Automation

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There are various methods to control a powered AFO. As different as they are in their approach each of them has certain advantages as well as difficulties. What is still needed is a robust control concept that meets the requirements for ankle gait assistance. A new, stiffness-control model has been developed that divides the stance phase of gait into five zones using either velocity or stiffness control for each zone. The design and implementation of this new control algorithm as well as some first test results are presented.

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Section: Discussionmentioning

confidence: 95%

“…9. Ankle Angle Divided Into Zones for One Gait Cycle [8] force, is used as well to zero the robot. In order to detect the transitions between the zones, a heel and toe switch is needed.…”

Section: Methodsmentioning

confidence: 99%

“…The theoretical foundation for a very promising new method has been developed by Sugar and Hollander [7], [8]. Their approach is a mixture between stiffness control and velocity control.…”

Section: The Robust Control Conceptmentioning

confidence: 99%

Section: B Combination Of Velocity and Stiffness Controlmentioning

confidence: 99%

See 2 more Smart Citations

Design, implementation and test results of a robust control method for a powered ankle foot orthosis (AFO)

Boehler

Hollander²,

Sugar

et al. 2008

2008 IEEE International Conference on Robotics and Automation

Self Cite

View full text Add to dashboard Cite

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“…This section begins with the brief introduction of the variable impedance controller commonly used in the control of prostheses [12], [19], [33]. Then, the novel real-time optimizationbased prostheses controller, proposed in [41] and validated in [44] is revisited.…”

Section: Prosthetic Controller Designmentioning

confidence: 99%

Multicontact Locomotion on Transfemoral Prostheses via Hybrid System Models and Optimization-Based Control

Zhao

Horn

Reher

et al. 2016

IEEE Trans. Automat. Sci. Eng.

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Lower-limb prostheses provide a prime example of cyber-physical systems (CPSs) requiring the synergistic development of sensing, algorithms, and controllers. With a view towards better understanding CPSs of this form, this paper presents a systematic methodology using multidomain hybrid system models and optimization-based controllers to achieve human-like multicontact prosthetic walking on a custom-built prosthesis: AMPRO. To achieve this goal, unimpaired human locomotion data is collected and the nominal multicontact human gait is studied. Inspired by previous work which realized multicontact locomotion on the bipedal robot AMBER2, a hybrid system-based optimization problem utilizing the collected reference human gait as reference is utilized to formally design stable multicontact prosthetic gaits that can be implemented on the prosthesis directly. Leveraging control methods that stabilize bipedal walking robots-control Lyapunov function-based quadratic programs coupled with variable impedance control-an online optimization-based controller is formulated to realize the designed gait in both simulation and experimentally on AMPRO. Improved tracking and energy efficiency are seen when this methodology is implemented experimentally. Importantly, the resulting multicontact prosthetic walking captures the essentials of natural human walking both kinematically and kinetically.Note to Practitioners-Variable impedance control, as one of the most popular prosthetic controllers, has been used widely on powered prostheses with notable success. However, due to the passivity of this controller, heuristic feedback is required to adjust the control parameters for different subjects and motion modes. The end result is extensive testing time for users, coupled with non-optimal performance of prostheses. Motivated by the shortcomings in the current state-of-the-art, this work proposes a novel systematic methodology-including gait generation and optimization-based control based on a multidomain hybrid system-to achieve prosthetic walking for a given subject. aims to improve control optimality and efficiency while potentially reducing clinical tuning. The overarching technology utilized in this paper is the use of nominal human trajectories coupled with formal models and controllers that circumvent the need for excessive hand-tuning. In particular, rather than using a prerecorded trajectory (as is common), this work takes a different approach by using a human-inspired optimization problem to design a human-like gait for the amputee automatically. The proposed optimization framework uses the trajectory of a healthy subject as the reference and is subject to specific constraints (to ensure smooth transitions, torque and angle limitations) such that the output gait is applicable for implementation on the prosthetic device directly. The results of the offline optimization are then utilized to synthesize an online real-time optimization-based feedback controller that allows for pointwise optimal tracking on the prosthesis, thereby impr...

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Wearable Carbon Nanotube‐Spandex Textile Yarns for Knee Flexion Monitoring

Fay

Mannering

Jeiranikhameneh

et al. 2022

Advanced Sensor Research

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Carbon nanotube-spandex textiles are rapidly gaining in popularity as sensors for human motion, yet their use as-and comparison to-viable clinical-based instrumentation has not been thoroughly investigated. Herein, the use of novel yarn-based sensors that show excellent characteristics, ideal for joint kinematic sensing, is described. Knee kinematic monitoring of nine healthy participants while walking on a treadmill is examined. This is enabled through a 3D-printed knee brace integrated with a wireless transmission device. The design, development, and testing of the wearable device is presented along with wireless data capture and processing. Additionally, the findings are compared in vivo to those reported by a reference optoelectronic measurement system (KneeKG) for validation purposes. The results show a high correlation between both systems, with an average Pearson's r-value of 0.89 across each corresponding knee. This study is the first to explore the use of these novel yarn sensors for sagittal knee kinematic monitoring on participants during trials and validate the findings via an optoelectronic measurement system.

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A Robust Control Concept for Robotic Ankle Gait Assistance

Cited by 14 publications

References 12 publications

Design, implementation and test results of a robust control method for a powered ankle foot orthosis (AFO)

Design, implementation and test results of a robust control method for a powered ankle foot orthosis (AFO)

Multicontact Locomotion on Transfemoral Prostheses via Hybrid System Models and Optimization-Based Control

Wearable Carbon Nanotube‐Spandex Textile Yarns for Knee Flexion Monitoring

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