Design and Control of a Pneumatic Artificial Muscle Actuated Above-Knee Prosthesis

2011 ◽  
Vol 5 (3) ◽  
Author(s):  
Garrett Waycaster ◽  
Sai-Kit Wu ◽  
Xiangrong Shen
Keyword(s):  
Control Algorithm ◽  
Knee Prosthesis ◽  
Radial Profile ◽  
Artificial Muscle ◽  
Torque Control ◽  
Effective Control ◽  
Pneumatic Artificial Muscle ◽  
Knee Prostheses ◽  
Control Approach ◽  
Highly Nonlinear

This paper presents the authors’ investigation results of applying the pneumatic artificial muscle actuation to above-knee prostheses. As a well-known muscle actuator, the pneumatic artificial muscle actuator features a number of unique advantages, including high power density, and similar elastic characteristics to biological muscles. Despite multiple applications in related areas, the application of pneumatic artificial muscle in above-knee prostheses has not been explored. Inspired by this fact, the research presented in this paper aims to develop a pneumatic artificial muscle-actuated above-knee prosthesis, with three specific objectives: (1) demonstrate the pneumatic artificial muscle actuation’s capability in generating sufficient torque output to meet the locomotive requirements; (2) develop an effective control approach to enable the restoration of locomotive functions; (3) conduct preliminary testing of the prosthesis prototype on a healthy subject through a specially designed able-body adaptor. In the prosthesis design, an agonist–antagonist layout is utilized to obtain a bidirectional motion. To minimize the radial profile, an open-frame structure is used, with the purpose of allowing the expansion of the muscle actuators into the center space without interference. Also, the muscle actuator parameters are calculated to provide sufficient torque capacity (up to 140 N m) to meet the requirements of level walking. According to this design, the fabricated prototype weighs approximately 3 kg, with a range of motion of approximately 100°. For the control of the prosthesis, a model-based torque control algorithm is developed based on the sliding mode control approach, which provides robust torque control for this highly nonlinear system. Combining this torque control algorithm with an impedance-based torque command generator (higher-level control algorithm), the fabricated prosthesis prototype has demonstrated a capability of providing a natural gait during treadmill walking experiments.

A Pneumatic Artificial Muscle Actuated Above-Knee Prosthesis

2010 ◽  
Author(s):  
Garrett Waycaster ◽  
Sai-Kit Wu ◽  
Xiangrong Shen
Keyword(s):  
Sliding Mode ◽  
Mechanical Design ◽  
Knee Prosthesis ◽  
Artificial Muscle ◽  
Torque Control ◽  
Stair Climbing ◽  
Pneumatic Artificial Muscle ◽  
Control Approach ◽  
Energy Consuming ◽  
And Control

This paper describes the mechanical design and control approach for an above-knee (AK) prosthesis actuated by pneumatic artificial muscle. Pneumatic artificial muscle (PAM) affords great potential in prosthetics, since this type of actuator features a high power density, and similar characteristics to human muscles. However, there is no application of PAM in AK prosthetics in existing literature to the best knowledge of the authors. In this paper, a design of the prosthesis is presented, which provides sufficient actuation torque for the knee joint in energy consuming locomotive functions such as fast walking and stair climbing. The corresponding control approach is also presented, which combines an impedance-based locomotive controller with a lower-level sliding-mode torque control approach. Experiments on the proposed AK prosthesis have also been conducted to demonstrate the ability to mimic normal gait characteristics.

A Pneumatic Artificial Muscle Articulated Knee Prosthesis

2010 ◽  
Author(s):  
Garrett Waycaster ◽  
Sai-Kit Wu ◽  
Xiangrong Shen
Keyword(s):  
Mechanical Design ◽  
Knee Prosthesis ◽  
Artificial Muscle ◽  
Stair Climbing ◽  
Pneumatic Artificial Muscle ◽  
Motion Controller ◽  
Control Approach ◽  
Energy Consuming ◽  
Human Motor ◽  
And Control

This paper describes the mechanical design and control approach for an above-knee (AK) prosthesis actuated by pneumatic artificial muscle. Pneumatic artificial muscle (PAM) affords great potential in prosthetics, since this type of actuator features a high power density, and similar characteristics to human muscles. However, there is no application of PAM in AK prosthetics in existing literature to the best knowledge of the authors. In this paper, a design of the prosthesis is presented, which provides sufficient actuation torque for the knee joint in energy consuming locomotive functions such as fast walking and stair climbing. The corresponding control approach is developed to mimic the human motor control in locomotive functions, which includes a lower-level equilibrium-point hypothesis-inspired motion controller, and a higher-level joint-behavior-based motion planner.

Performance improvement of direct torque control for induction motor drive via fuzzy logic-feedback linearization

2019 ◽  
Vol 38 (2) ◽  
pp. 672-692 ◽  
Author(s):  
Abdelkarim Ammar
Keyword(s):  
Fuzzy Logic ◽  
Robust Control ◽  
Feedback Linearization ◽  
Control Algorithm ◽  
Direct Torque Control ◽  
Torque Control ◽  
Motor Drive ◽  
Induction Motor Drive ◽  
Content Type ◽  
Control Approach

Purpose This paper aims to propose an improved direct torque control (DTC) for the induction motor’s performance enhancement using dual nonlinear techniques. The exact feedback linearization is implemented to create a linear decoupled control. Besides, the fuzzy logic control approach has been inserted to generate the auxiliary control input for the feedback linearization controller. Design/methodology/approach To improve the DTC for induction motor drive, this work suggests the incorporation of two nonlinear approaches. As the classical feedback linearization suffers while the presence of uncertainties and modeling inaccuracy, it is recommended to be associated to another robust control approach to compensate the uncertainties of the model and make a robust control versus the variations of the machine parameters. Therefore, fuzzy logic controllers will be integrated as auxiliary inputs to the feedback linearization control law. Findings The simulation and the experimental validation of the proposed control algorithm show that the association of dual techniques can effectively achieve high dynamic behavior and improve the robustness against parameters variation and external disturbances. Moreover, the space vector modulation is used to preserve a fixed switching frequency, reduce ripples and low switching losses. Practical implications The theoretical, simulation and experimental studies prove that the proposed control algorithm can be used on different AC machines for variable speed drive applications such as oil drilling, traction systems and wind energy conversion systems. Originality/value The proposed DTC strategy has been developed theoretically and realized through simulation and experimental implementation. Different operation conditions have been conducted to check the ability and robustness of the control strategy, such as steady state, speed reversal maneuver, low-speed operation and parameters variation test with load application.

Design and Control of a Compact and Flexible Pneumatic Artificial Muscle Actuation System: Part Two—Robust Control

2011 ◽  
Author(s):  
Sai-Kit Wu ◽  
Garrett Waycaster ◽  
Tad Driver ◽  
Xiangrong Shen
Keyword(s):  
Robust Control ◽  
Nonlinear Model ◽  
Sliding Mode ◽  
Artificial Muscle ◽  
Control Approach ◽  
Actuation System ◽  
Highly Nonlinear ◽  
Pressure Dynamics ◽  
System Part ◽  
And Control

A robust control approach is presented in this part of the paper, which provides an effective servo control for the novel PAM actuation system presented in Part I. Control of PAM actuation systems is generally considered as a challenging topic, due primarily to the highly nonlinear nature of such system. With the introduction of new design features (variable-radius pulley and spring-return mechanism), the new PAM actuation system involves additional nonlinearities (e.g. the nonlinear relationship between the joint angle and the actuator length), which further increasing the control difficulty. To address this issue, a nonlinear model based approach is developed. The foundation of this approach is a dynamic model of the new actuation system, which covers the major nonlinear processes in the system, including the load dynamics, force generation from internal pressure, pressure dynamics, and mass flow regulation with servo valve. Based on this nonlinear model, a sliding mode control approach is developed, which provides a robust control of the joint motion in the presence of model uncertainties and disturbances. This control was implemented on an experimental setup, and the effectiveness of the controller demonstrated by sinusoidal tracking at different frequencies.

A Monopropellant-Powered Muscle Actuation System

2010 ◽  
Author(s):  
Xiangrong Shen ◽  
Daniel Christ
Keyword(s):  
Controller Design ◽  
Artificial Muscle ◽  
High Energy ◽  
Mobile Systems ◽  
High Energy Density ◽  
Robotic Systems ◽  
Effective Control ◽  
Future Application ◽  
Actuation System ◽  
Highly Nonlinear

This paper describes the design and control of a new monopropellant-powered muscle actuation system for robotic systems, especially the mobile systems inspired by biological principles. Based on the pneumatic artificial muscle, this system features a high power density, as well as characteristics similar to biological muscles. By introducing the monopropellant as the energy storage media, this system utilizes the high energy density of liquid fuel and provides a high-pressure gas supply with a simple structure in a compact form. This addresses the limitations of pneumatic supplies on mobile devices and thus is expected to facilitate the future application of artificial muscles on bio-robotic systems. In this paper, design of the monopropellant-powered muscle actuation system is presented as well as a robust controller design that provides effective control for this highly nonlinear system. To demonstrate the proposed muscle actuation system, an experimental prototype was constructed on which the proposed control algorithm provides good tracking performance.

Walking-Stair Climbing Control for Powered Knee Prostheses

2016 ◽  
Author(s):  
Molei Wu ◽  
Xiangrong Shen
Keyword(s):  
Impedance Control ◽  
Knee Prosthesis ◽  
Stair Climbing ◽  
Knee Joints ◽  
Knee Prostheses ◽  
Control Approach ◽  
Prosthetic Joints ◽  
Real Time Measurement ◽  
Human Subject Testing ◽  
Finite State

Recent progresses in powered lower-limb prostheses have the potential of enabling amputee users to conduct energetically demanding locomotive tasks, which are usually beyond the capability of traditional unpowered prostheses. Realizing such potential, however, requires responsive and reliable control of the power provided by prosthetic joints. In this paper, an integrated walking-stair climbing control approach is presented for transfemoral prostheses with powered knee joints. Leveraging the similarities between walking and stair climbing, this new approach adopts the general finite-state impedance control framework. Furthermore, important modifications are introduced to model the biomechanical characteristics that are beyond the capability of standard impedance control. The transition between the walking and stair-climbing modes is triggered through the real-time measurement of the spatial orientation of the user’s thigh, which provides a reliable indicator of the user’s intention of making such transition. This new control approach has been implemented on a powered knee prosthesis, and its effectiveness was demonstrated in human subject testing.

scholarly journals Position/force control of master–slave antagonistic joint actuated by water hydraulic artificial muscles

2019 ◽  
Vol 16 (3) ◽  
pp. 172988141985398
Author(s):  
Dayong Ning ◽  
Jinkai Che ◽  
Zengmeng Zhang ◽  
Hao Tian ◽  
Jiaoyi Hou ◽  
...  
Keyword(s):  
Rotation Angle ◽  
Weight Ratio ◽  
Artificial Muscle ◽  
Force Transducer ◽  
Torque Control ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Proportional Integral Derivative ◽  
Proportional Integral ◽  
Water Hydraulic

Because of the high force–weight ratio of water hydraulic artificial muscle and its high compatibility with an underwater environment, the water hydraulic artificial muscle has received increasing attention due to its potential uses in marine engineering applications. The master–slave anthropopathic joint actuated by water hydraulic artificial muscles is light and small, and it has good maneuverability for underwater manipulators. However, the control methodologies for water hydraulic artificial muscle joint have not been thoroughly explored to date. This article introduces a master–slave control system of isomorphic artificial muscle joints. The water hydraulic artificial muscle joint acts as a slave joint working under the sea, and the pneumatic artificial muscle joint acts as a master joint that is operated by people. The rotation angle signal of the pneumatic artificial muscle joint is fed back as the input to regulate the rotation angle of the water hydraulic artificial muscle joint through a proportional–integral–derivative control. Meanwhile, the torque of the pneumatic artificial muscle joint is controlled by a proportional–integral–derivative controller based on the feedback of a two-force-transducer system in the water hydraulic artificial muscle joint as input. Therefore, the operator can control the movement and feel the load of the water hydraulic artificial muscle slave joint. Master–slave control experiments were performed, and the position/torque control results were analyzed using various loads and torque gains. This study contributes to the design and control of an anthropopathic underwater manipulator.

An enhanced computed-torque control algorithm for robot manipulators

1998 ◽  
Vol 212 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Q Li ◽  
S K Tso ◽  
A N Poo
Keyword(s):  
Control Algorithm ◽  
Internal Model Control ◽  
Torque Control ◽  
Simulation Studies ◽  
Control Approach ◽  
Computed Torque Control ◽  
Control Scheme ◽  
Model Control ◽  
Theoretical Analyses ◽  
Computed Torque

An enhanced computed-torque control approach, which is developed based on the intuitive design concept of the internal model control structure, is proposed in this paper. Both theoretical analyses and simulation studies on a two-link robot prove that the robustness of this enhanced algorithm can surpass that of the conventional computed-torque control scheme by a large extent.

Design and Control of Chemomuscle: A Liquid-Propellant-Powered Muscle Actuation System

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Xiangrong Shen ◽  
Daniel Christ
Keyword(s):  
Liquid Fuel ◽  
Artificial Muscle ◽  
High Energy ◽  
Mobile Systems ◽  
High Energy Density ◽  
Effective Control ◽  
Future Application ◽  
Actuation System ◽  
Highly Nonlinear ◽  
And Control

This paper describes the design and control of a new chemomuscle actuation system for robotic systems, especially the mobile systems inspired by biological principles. Developed based on the pneumatic artificial muscle, a chemomuscle actuation system features a high power density, as well as similar characteristics to the biological muscles. Furthermore, by introducing monopropellant (a special type of liquid fuel) as the energy storage media, the chemomuscle system leverages the high energy density of liquid fuel and provides a compact form of high-pressure gas supply with a simple structure. The introduction of monopropellant addresses the limitation of pneumatic supply on mobile devices and thus is expected to facilitate the future application of artificial muscle on biorobotic systems. In this paper, the design of a chemomuscle actuation system is presented, as well as a robust controller design that provides effective control for this highly nonlinear system. To demonstrate the proposed chemomuscle actuation system, an experimental prototype is constructed, on which the proposed control algorithm provides good tracking performance.

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