A Monopropellant-Powered Muscle Actuation System

Author(s):  
Xiangrong Shen ◽  
Daniel Christ

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.

Author(s):  
Xiangrong Shen ◽  
Daniel Christ

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.


Author(s):  
Garrett Waycaster ◽  
Sai-Kit Wu ◽  
Tad Driver ◽  
Xiangrong Shen

This paper describes the design and control of a compact and flexible pneumatic artificial muscle (PAM) actuation system for bio-robotic systems. The entire paper is divided into two parts, with the first part covering the mechanism design and the second part covering the corresponding controller design. This novel system presented in this part incorporates two new features, including a variable-radius pulley based PAM actuation mechanism, and a spring-return mechanism to replace the PAM in the “weak” direction. With the pulley radius as a function of the joint angle, this new feature enables the designer to freely modulate the shape of the torque curve, and thus achieves a significantly higher flexibility than the traditional configuration. The other new feature, the spring-return mechanism, is inspired by the fact that a large number of bio-robotic systems require a significantly larger torque in one direction than the other.


Author(s):  
Sai-Kit Wu ◽  
Garrett Waycaster ◽  
Tad Driver ◽  
Xiangrong Shen

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.


Author(s):  
Dominik Scholtes ◽  
Stefan Seelecke ◽  
Gianluca Rizzello ◽  
Paul Motzki

Abstract Within industrial manufacturing most processing steps are accompanied by transporting and positioning of workpieces. The active interfaces between handling system and workpiece are industrial grippers, which often are driven by pneumatics, especially in small scale areas. On the way to higher energy efficiency and digital factories, companies are looking for new actuation technologies with more sensor integration and better efficiencies. Commonly used actuators like solenoids and electric engines are in many cases too heavy and large for direct integration into the gripping system. Due to their high energy density shape memory alloys (SMA) are suited to overcome those drawbacks of conventional actuators. Additionally, they feature self-sensing abilities that lead to sensor-less monitoring and control of the actuation system. Another drawback of conventional grippers is their design, which is based on moving parts with linear guides and bearings. These parts are prone to wear, especially in abrasive environments. This can be overcome by a compliant gripper design that is based on flexure hinges and thus dispenses with joints, bearings and guides. In the presented work, the development process of a functional prototype for a compliant gripper driven by a bistable SMA actuation unit for industrial applications is outlined. The focus lies on the development of the SMA actuator, while the first design approach for the compliant gripper mechanism with solid state joints is proposed. The result is a working gripper-prototype which is mainly made of 3D-printed parts. First results of validation experiments are discussed.


2019 ◽  
Vol 804 ◽  
pp. 59-62
Author(s):  
Min Wei ◽  
Wei Li ◽  
Zhen Qiang Song ◽  
Shijie Zhu

The dielectric elastomer (DE) has the advantages of large deformation ability, fast response speed, low price and high energy density. Therefore, DE has great prospects as artificial muscle and flexible robot. The purpose of the research is to clarify the mechanical behavior for acrylate dielectric elastomer by tensile test, fatigue test and viscoelasticity measurement.


2021 ◽  
Vol 7 ◽  
Author(s):  
Xiaozhong Zhou ◽  
Zhaoyi Qi ◽  
Qiang Liu ◽  
Jibin Tian ◽  
Mingxia Liu ◽  
...  

With unique advantages, such as high energy density, long lifespan and environmental friendliness, lithium-ion batteries (LIBs) have been widely used in various portable electronics, and placed great expectations on the application in electric vehicles. To meet the ever-increasing high-energy-density demand of the next-generation LIBs, silicon suboxide SiOx(0 < x < 2) has been considered as one of the most promising anode materials, due to its high mass specific capacity, good cycling performance, proper working potential, low cost, and environmental friendliness. However, there are still several drawbacks before the application of SiOx, such as low intrinsic electronic conductivity and high irreversible capacity in the first cycle, which lead to low electrochemical activity and low initial coulombic efficiency (ICE). To tackle these issues, extensive efforts have been made and remarkable progresses have achieved in recent years. Here, latest developments of SiOx-based anodes are briefly reviewed, especially on the subject of metal/metal oxide doping on SiOx-based electrode materials, and the future application of SiOx anodes in rechargeable LIBs is also prospected.


Robotica ◽  
2009 ◽  
Vol 27 (1) ◽  
pp. 131-146 ◽  
Author(s):  
Vishalini Bundhoo ◽  
Edmund Haslam ◽  
Benjamin Birch ◽  
Edward J. Park

SUMMARYIn this paper, a new biomimetic tendon-driven actuation system for prosthetic and wearable robotic hand applications is presented. It is based on the combination of compliant tendon cables and one-way shape memory alloy (SMA) wires that form a set of agonist–antagonist artificial muscle pairs for the required flexion/extension or abduction/adduction of the finger joints. The performance of the proposed actuation system is demonstrated using a 4 degree-of-freedom (three active and one passive) artificial finger testbed, also developed based on a biomimetic design approach. A microcontroller-based pulse-width-modulated proportional-derivation (PWM-PD) feedback controller and a minimum jerk trajectory feedforward controller are implemented and tested in anad hocfashion to evaluate the performance of the finger system in emulating natural joint motions. Part II describes the dynamic modeling of the above nonlinear system, and the model-based controller design.


2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Lei Qin ◽  
Jiawei Cao ◽  
Yucheng Tang ◽  
Jian Zhu

Dielectric elastomer actuators (DEAs) exhibit interesting muscle-like attributes including large voltage-induced deformation and high energy density, thus can function as artificial muscles for soft robots/devices. This paper focuses on soft planar DEAs, which have extensive applications such as artificial muscles for jaw movement, stretchers for cell mechanotransduction, and vibration shakers for tactile feedback, etc. Specifically, we develop a soft planar DEA, in which compression springs are employed to make the entire structure freestanding. This soft freestanding actuator can achieve both linear actuation and turning without increasing the size, weight, or structural complexity, which makes the actuator suitable for driving a soft crawling robot. Furthermore, its simple structure and homogeneous deformation allow for analytic modeling, which can be used to interpret the large voltage-induced deformation and interesting mechanics phenomenon (i.e., wrinkling and electromechanical instability). A preliminary demonstration showcases that this soft planar actuator can be employed as an artificial muscle to drive a soft crawling robot.


2017 ◽  
Vol 114 (14) ◽  
pp. 3584-3589 ◽  
Author(s):  
Ying Zhang ◽  
Wei Luo ◽  
Chengwei Wang ◽  
Yiju Li ◽  
Chaoji Chen ◽  
...  

Lithium metal anode with the highest capacity and lowest anode potential is extremely attractive to battery technologies, but infinite volume change during the Li stripping/plating process results in cracks and fractures of the solid electrolyte interphase, low Coulombic efficiency, and dendritic growth of Li. Here, we use a carbonized wood (C-wood) as a 3D, highly porous (73% porosity) conductive framework with well-aligned channels as Li host material. We discovered that molten Li metal can infuse into the straight channels of C-wood to form a Li/C-wood electrode after surface treatment. The C-wood channels function as excellent guides in which the Li stripping/plating process can take place and effectively confine the volume change that occurs. Moreover, the local current density can be minimized due to the 3D C-wood framework. Therefore, in symmetric cells, the as-prepared Li/C-wood electrode presents a lower overpotential (90 mV at 3 mA⋅cm−2), more-stable stripping/plating profiles, and better cycling performance (∼150 h at 3 mA⋅cm−2) compared with bare Li metal electrode. Our findings may open up a solution for fabricating stable Li metal anode, which further facilitates future application of high-energy-density Li metal batteries.


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