scholarly journals CONTROL NOVEL MODEL OF KNEE CPM DEVICE

2009 ◽  
Vol 12 (4) ◽  
pp. 18-29
Author(s):  
Thanh Diep Cong Tu

In recent years, CPM - Continuous Passive Motion has been proved to be one of the most effective therapeutic methods for patients who have problems with motion such as spinal cord injury, ankle and knee injury, parkinson and so on. Many commercial CPM devices are found in market but all of them use motors as the main actuators. The lack of human compliance of electric actuators, which are commonly used in these machines, makes them potentially harmful to patients. An interesting alternative, to electric actuators for medical purposes, particularly promising for rehabilitation, is a pneumatic artificial muscle (PAM) actuator because of its high power/weight ratio and compliance properties. However, the highly nonlinear and hysteresis of PAM make it the challenging for design and control. In this study, a PID compensation using neural network control is studied to improve the control performance of the novel model of Knee CPM device.

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.


Robotica ◽  
2018 ◽  
Vol 36 (9) ◽  
pp. 1333-1362
Author(s):  
Ho Pham Huy Anh ◽  
Cao Van Kien ◽  
Nguyen Thanh Nam

SUMMARYThis paper proposes a detailed investigation on the new neural-based feed-forward PID direct force control (FNN-PID-DF) approach applied to a highly nonlinear 2-axes pneumatic artificial muscle (PAM) manipulator in order to ameliorate its force output performance. Founded on the novel inverse neural NARX model dynamically identified to learn well all nonlinear characteristics of the contact force dynamics of the 2-axes PAM-based manipulator, the novel proposed neural FNN-PID-DF force controller is innovatively implemented in order to directly force control the 2-axes PAM robot system used as a rehabilitation device subjected to internal systematic interactions and external contact force deviations. The performance of the experimental tests has proven the advantages and merits of the new force control method compared to the classical PID force control method. The new neural FNN-PID-DF force controller guides the wrist/hand of subject/patient to successfully generate the predefined desired force values.


2020 ◽  
Vol 10 (1) ◽  
pp. 5276-5280
Author(s):  
S. Z. Ying ◽  
N. K. Al-Shammari ◽  
A. A. Faudzi ◽  
Y. Sabzehmeidani

This paper presents the development of a soft rehabilitation robot to conduct Continuous Passive Motion (CPM) for hand rehabilitation. The main contribution of this work is the implementation of a McKibben actuator as an artificial muscle due to its proven advantages: simple structure, light weight, and high power-to-weight ratio. The development worked successfully when tested on a healthy subject, where the flexion and extension of the finger were controlled with an antagonistic pair of actuators. However, there is a limitation of the McKibben actuator regarding its length-dependency. In this research, the concept of a pulley system was proposed to overcome this limitation. Although there is a friction factor that reduces the contracting displacement by at least 15% of the original displacement, a pulley is still a potential solution as it can reduce the installation space of the actuator from 40 to 15cm while still producing sufficient force for the finger motion. Throughout this research, it was found that the pattern of the flexor pulley system is affecting the system’s efficiency in terms of motion assistance.


2006 ◽  
Vol 3 (3) ◽  
pp. 191-197 ◽  
Author(s):  
N. Saga ◽  
J. Nagase ◽  
T. Saikawa

This article reports the pneumatic artificial muscles based on biomechanical characteristics of human muscles. A wearable device and a rehabilitation robot that assist a human muscle should have characteristics similar to those of human muscle. In addition, since the wearable device and the rehabilitation robot should be light, an actuator with a high power to weight ratio is needed. At present, the McKibben type is widely used as an artificial muscle, but in fact its physical model is highly nonlinear. Therefore, an artificial muscle actuator has been developed in which high-strength carbon fibres have been built into the silicone tube. However, its contraction rate is smaller than the actual biological muscles. On the other hand, if an artificial muscle that contracts axially is installed in a robot as compactly as the robot hand, big installing space is required. Therefore, an artificial muscle with a high contraction rate and a tendon-driven system as a compact actuator were developed, respectively. In this study, we report on the basic structure and basic characteristics of two types of actuators.


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.


2013 ◽  
Vol 8 (1-2) ◽  
pp. 70-76
Author(s):  
József Sárosi ◽  
Zoltán Fabulya

The newest and most promising type of pneumatic actuators is the pneumatic artificial muscle (PAM). Different designs have been developed, but the McKibben muscle is the most popular and is made commercially available by different companies (e. g. Fluidic Muscle manufactured by Festo Company and Shadow Air Muscle manufactured by Shadow Robot Company). Pneumatic artificial muscles have a wide range of use in industrial and medical fields. There are a lot of advantages of these muscles like the high strength, good power-weight ratio, low price, little maintenance needed, great compliance, compactness, inherent safety and usage in rough environments. The main disadvantage is that their dynamic behaviour is highly nonlinear. The most often mentioned characteristic of PAMs is the force as a function of pressure and contraction. In this paper the newest function approximations for the force generated by Fluidic Muscles are investigated in MS Excel.


2014 ◽  
Vol 8 (4) ◽  
Author(s):  
Shanthanu Chakravarthy ◽  
K. Aditya ◽  
Ashitava Ghosal

Robotic surgical tools used in minimally invasive surgeries (MIS) require miniaturized and reliable actuators for precise positioning and control of the end-effector. Miniature pneumatic artificial muscles (MPAMs) are a good choice due to their inert nature, high force to weight ratio, and fast actuation. In this paper, we present the development of miniaturized braided pneumatic muscles with an outer diameter of ∼1.2 mm, a high contraction ratio of about 18%, and capable of providing a pull force in excess of 4 N at a supply pressure of 0.8 MPa. We present the details of the developed experimental setup, experimental data on contraction and force as a function of applied pressure, and characterization of the MPAM. We also present a simple kinematics and experimental data based model of the braided pneumatic muscle and show that the model predicts contraction in length to within 20% of the measured value. Finally, a robust controller for the MPAMs is developed and validated with experiments and it is shown that the MPAMs have a time constant of ∼10 ms thereby making them suitable for actuating endoscopic and robotic surgical tools.


2007 ◽  
Vol 345-346 ◽  
pp. 1249-1252 ◽  
Author(s):  
Kyoung Rae Cha ◽  
Gwang Ho Kim ◽  
Ju Hwan Kim ◽  
Sang Hwa Jeong

In recent years, as the robot technology is developed, the researches on the artificial muscle actuator that enables robot to move dexterously like biological organ become active. Actuators are one of the key technologies underpinning robotics. Particularly breakthroughs of power-to-weight ratio or energy-density in actuator technology have significant impacts upon the design and the control of robotic systems. The widely used materials for artificial muscle are the shape memory alloy and electro-active polymer. These actuators have the higher energy density than the electromechanical actuators such as the electric motor. However, there are some drawbacks because these actuators have the hysteretic dynamic characteristics. In this paper, the segment control for reducing the hysteresis of SMA is proposed and the simulation of an anthropomorphic robotic hand is performed using ADAMS. A new approach to design and control of SMA actuators is presented. SMA wire is divided into many segments and their thermal states are controlled individually in a binary manner(ON/OFF). The basic experiment for evaluating the dynamic characteristics of SMA wire actuator is performed.


2014 ◽  
Vol 644-650 ◽  
pp. 879-883
Author(s):  
Jing Jing Yu

In various forms of movement of finger rehabilitation training, Continuous Passive Motion (CPM) of single degree of freedom (1 DOF) has outstanding application value. Taking classic flexion and extension movement for instance, this study collected the joint angle data of finger flexion and extension motion by experiments and confirmed that the joint motion of finger are not independent of each other but there is certain rule. This paper studies the finger joint movement rule from qualitative and quantitative aspects, and the conclusion can guide the design of the mechanism and control method of finger rehabilitation training robot.


Healthcare ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 126
Author(s):  
Hai-Feng Ling ◽  
Zheng-Lian Su ◽  
Xun-Lin Jiang ◽  
Yu-Jun Zheng

In a large-scale epidemic, such as the novel coronavirus pneumonia (COVID-19), there is huge demand for a variety of medical supplies, such as medical masks, ventilators, and sickbeds. Resources from civilian medical services are often not sufficient for fully satisfying all of these demands. Resources from military medical services, which are normally reserved for military use, can be an effective supplement to these demands. In this paper, we formulate a problem of integrated civilian-military scheduling of medical supplies for epidemic prevention and control, the aim of which is to simultaneously maximize the overall satisfaction rate of the medical supplies and minimize the total scheduling cost, while keeping a minimum ratio of medical supplies reservation for military use. We propose a multi-objective water wave optimization (WWO) algorithm in order to efficiently solve this problem. Computational results on a set of problem instances constructed based on real COVID-19 data demonstrate the effectiveness of the proposed method.


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