An Innovative Design of Artificial Knee Joint Actuator With Energy Recovery Capabilities

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Roberta Alò ◽  
Francesco Bottiglione ◽  
Giacomo Mantriota

The actuation systems of lower limbs exoskeletons have been extensively investigated and, presently, a great effort is aimed at reducing the weight and improving the efficiency, thus increasing the operating range for battery-operated devices. In this work, an innovative and more efficient actuation system to power the knee joint is proposed. The key and nonconventional elements of this alternative design are a flywheel and a micro infinitely variable transmission (IVT). This particular powertrain configuration permits to exploit efficiently the dynamics of human locomotion, which offers the possibility to recover energy. By means of simulations of level ground walking and running, it is here demonstrated how storing energy in the flywheel permits to reduce the energy consumption and to downsize the electric motor.

2017 ◽  
Vol 11 (3) ◽  
pp. 361-367
Author(s):  
Roberta Aló ◽  
◽  
Francesco Bottiglione ◽  
Giacomo Mantriota

The efficient energetics of human walking could possibly be used to fulfill the total power requirement of human knee, without requiring any additional sources of energy. This study intends to addresses this issue by examining the idea of a novel self-powered actuator for artificial knee joints of wearable robots. The self-powered Flywheel-Infinitely Variable Transmission (F-IVT) is an actuator whose only source of power is a flywheel that stores and delivers energy from and to the knee joint by changing the speed ratio of the IVT according to the phase of the gait cycle. This study evaluates the efficacy of this novel actuator by estimating the amount of energy it can deliver to the knee joint while the subject walks on level ground at varied speeds.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Roberta Alò ◽  
Francesco Bottiglione ◽  
Giacomo Mantriota

The human knee absorbs more energy than it expends in level ground walking. For this reason it would be useful if the actuation system of a wearable robot for lower limbs was able to recover energy thus improving portability. Presently, we recognize three promising technologies with energy recovery capabilities already available in the literature: the Series Elastic Actuator (SEA), the Clutchable Series Elastic Actuator (C-SEA), and the flywheel Infinitely Variable Transmission (F-IVT) actuator. In this paper, a simulation model based comparison of the performance of these actuators is presented. The focus is on two performance indexes: the energy consumed by the electric motor per gait and the peak torque/power requested to the electric motor. Both quantities are related to the portability of the device: the former affects the size of the batteries for a given desired range; the latter affects the size and the weight of the electric motor. The results show that, besides some well-explained limitations of the presented methodology, the C-SEA is the most energy efficient whereas the F-IVT allows cutting down the motor torque/peak power strongly. The analysis also leads to defining how it is possible to improve the F-IVT to achieve a reduction of the energy consumption.


2021 ◽  
Vol 11 (6) ◽  
pp. 1780-1788
Author(s):  
Habaxi Kaken ◽  
Shanshan Wang ◽  
Wei Zhao ◽  
Baoerjiang Asihaer ◽  
Li Wang

This article studies the effects of arthroscopic imaging treatment and clinical rehabilitation of knee sports injuries. Arthroscopy was used to perform meniscus trimming and resection for 40 patients with knee sports injuries. The ages of the patients ranged from 20 to 60 years old. All patients received routine rehabilitation training such as continuous passive motion of the knee joint, biofeedback of the lower limbs, and air pressure therapy of the lower limbs. In addition, the control group was given muscle strength training, and the training began after the patients received the quadriceps muscle strength test. The removal of the joint cavity and the joint debridement has achieved satisfactory treatment results. In the experiment, the test cases were divided into two groups, and the sensor test platform was used for signal collection. Normal activities can be resumed 2 weeks after the operation. After a follow-up of 6 to 24 months, the knee joint pain disappeared, the joint was free of swelling, and the knee function was normal up to 93%. Arthroscopic reconstruction of the anterior and posterior cruciate ligament joint repair/reconstruction of the medial and posterolateral ligament knots is safe and feasible for the treatment of multiple ligament injuries of the knee joint. It has the advantages of less trauma and quick recovery. Early postoperative systemic and standardized rehabilitation exercises can obtain good knee joint function.


2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Ender İnce ◽  
Mehmet A. Güler

In the last few decades, power-split infinitely variable transmission (IVT) systems have attracted considerable attention as they ensure high driving comfort with high total efficiencies, especially in off-highway vehicles and agricultural machines. In this study, a novel power-split-input-coupled IVT system is developed. The effects of various dynamic parameters such as power flow and Willis transmission ratio on the mechanical efficiency of the systems are investigated. Kinematic analysis of the new system has been carried out. In addition power flow equations are derived as functions of the power that flows through the infinitely variable unit (IVU). The results indicate that the main parameters, which are strictly related to mechanical efficiency are the power and torque flows through the IVU.


Author(s):  
Fengyu Liu ◽  
Li Chen ◽  
Jian Yao ◽  
Chunhao Lee ◽  
Chi-kuan Kao ◽  
...  

Clutch-to-clutch shift technology is a key enabler for fast and smooth gear shift process for multi gear transmissions. However, conventional hydraulic actuation systems for clutches have drawbacks of low efficiency, oil leakage and inadequate robustness. Electromechanical devices offer potential alternative actuators. In this paper, a novel motor driven wedge-based clutch actuator, featuring self-reinforcement, is proposed. The design concept and physical structure are thoroughly described. Dynamic models for the actuation system and vehicle powertrain are validated by experiments. Upshift and downshift processes at different engine throttle openings, clutch clearances and friction coefficients are discussed. The results show that, the self-reinforcement ratio is tested as 9.6; at the same time, the shift quality is comparable to that of the conventional hydraulic actuated clutch in automatic transmissions in terms of the shift duration (about 1 s) and vehicle jerk (<10 m/s3). Taking advantage of fast response of the actuation DC motor, the wedge-based actuator is robust dealing with uncertain clutch clearance and friction coefficient. Therefore, the wedge-based clutch actuator has potential to provide acceptable performance for clutch-to-clutch shift.


Author(s):  
Rajiv Chaudhary ◽  
◽  
Alok Kumar Singh

Tracking the path of development in different Engineering disciplines, it can be easily observed that, right from the primitive stage, several tools, devices, and techniques may be identified, which happened by virtue of the evolution of human intelligence, getting transformed into various engineering applications. Although, later different engineering disciplines evolved, where most of the exhaustive development could be undertaken in that discipline. Likewise, in the field of mechanical engineering to various types of mechanical systems, according to the requirement in that field, were developed, in order to provide support of mechanization. Prime movers used to be an important part of these mechanical systems, which provided energy input as well as actuation required for providing the machines the desired kinematics. Most of the mechanical systems developed has been operated by conventional engine system using one or other fuel. Apart from the actuation by mechanical means, there are other means also through which mechanical actuation with better control, flexibility, and manipulation may be utilized in mechanical systems. A different category of systems, called Mechatronic systems has been developed in the recent past, which involves the vivid scope of use of techniques, devices, and components generally used in various other engineering fields of electrical, electronics, hydraulics, and pneumatics, etc. Subsequently, there have been several inventions, design & development which have added new levels in every field. Mechanical systems have been generally composed of various mechanical elements, which are designed to follow certain kinematics. The performance of the Actuation system plays an important role in the overall performance of the mechanical systems. There are several alternative actuation systems, which are not mechanical. These actuation systems may be categorized into electrical, electronics, hydraulic and pneumatic types. The features of these actuation systems, are so peculiar, that typical kinematic movement may be manipulated that too with more precision. Better control of mechanical systems may be realized, which is otherwise difficult with mechanical systems. In this paper, an effort has been made to review the possibilities, prospects as well as scope with various actuation systems.


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