• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.11
• /
• pp.1391-1398
• /
• 2011

Biomechanical analysis of arm motion during steering was performed using a motion analysis technique. Three-dimensional position data for each part of arm are fed into an interactive model combining a musculoskeletal arm model and the mechanical steering system to calculate joint angles and torques using inverse kinematic and dynamic analyses, respectively. The analysis shows that elbow pronation/supination, wrist flexion/extension, shoulder adduction/abduction, and shoulder flexion/extension have significant magnitudes. Sensitivity analysis of the arm joint motion with respect to seating posture and steering wheel configuration is carried out to investigate the qualitative influence of the seating posture and driver's seat configuration on the steering behavior.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.2
• /
• pp.157-168
• /
• 2008

Tightening of the screws in implant restorations should be accurate and precise. If applied torque is too low, screw loosening would be occurred. With too high torque, the screw fracture might take place. Various torque generating devices are developed and employed to apply a proper torque. The purpose of this investigation was to determine and compare the accuracy of the torque controllers. In this study, 4 types of torque controllers were used; electronic torque controller, torque limiting device, torque indicating device and contra angle torque driver. Digital torque gauge was employed to measure the de-torque value. Thirty cycles of tightening and loosening were done with each torque controller. All implant torque controllers have shown slight errors and deviations. The torque liming device exhibited the most accurate data. No significant difference was found among the mean de-torque values of the electronic torque controller, torque indicating device and contra angle torque driver. In the limitation of this study, it would be recommended that the implant torque controllers should be checked whether uniformed and precise torque can be generated and a measuring error should be corrected.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.3
• /
• pp.549-555
• /
• 2009

The purpose of this study was to quantify the isokinetic peak torque and range of motion at the shoulder in 8 national male volleyball players who played during the 2008 professional leagues. In this study the strength and range of motion data in the internal rotation(IR) and external rotation(ER) of shoulder joint were measured with isokinetic measurement system(Biodex Inc) and motion analysis system (Simi motion system Inc.) from 3 volleyball players with atrophy of the infrasupinatus and 5 volleyball players without atrophy of the infraspinatus. Peak torques were determined using isokinetic measurement on the shoulder joint rotator at the point of angular velocities of $60^{\circ}$/s. Significant difference was found in the peak torque, IR / ER ratio and the range of motion through assessment of the dominant shoulder between two groups. we recommended functional exercises that improve both external rotators strength and stretching exercise for internal rotation in the dominant side during the prevention programs in volleyball players.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.18 no.5
• /
• pp.642-648
• /
• 2008

A lot of researches on the redundant manipulators have been focused mainly on the minimization of joint torques. However, it is well-known that the most dynamic control algorithms using local joint torque minimization cause huge torques which can not be implemented by practical motor drivers. A new control algorithm which reduces considerably such a huge-required-torque problem is proposed in this paper. It adapts fuzzy logic and genetic algorithm to the conventional local joint torque minimization algorithm. The proposed algorithm is applied to a 3-DOF redundant planar robot. Simulation results show that the proposed algorithm works well.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.7
• /
• pp.610-614
• /
• 1991

This paper proposes a trajectory constrol fo a robot manipulator by using neural network. The inverse dynamic model of manipuator is learned by neural network. The manipulator is controlled by weight values of the learned neural network. The weight valuese is change with a torque of liner vontroller and a acceleration error. Phsically, the totlal torque for a manipualator is a sum of the liner controller torque and the nerural network controller torque. The proposed control effect is estimated by computer simulation.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.31 no.4
• /
• pp.310-315
• /
• 2015

Purpose: The purpose of this study was to measure the tightening torque for dental implant in dental laboratory and to analyze of the effects of different tightening torque. Materials and Methods: The tightening torque for dental implant in dental laboratory were measured by digital torque gauge. The length of abutment and analog were measured as tightening torque of manufacturer's instructions and the measured value. And the data were statically analyzed. Results: The mean tightening torque of implant screw in dental laboratory was $1.563{\pm}0.332Ncm$. The external type implant system of total length were showing no significant differences but the internal type implant system had difference significant (P < 0.05) when compared with tightening torque. Conclusion: The implant prosthesis should be made under manufacturer's instructions especially as tightening torque of screw. For the fidelity of implant prosthesis, dental technician should learn how to use the torque gauge.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.7 no.1
• /
• pp.21-27
• /
• 2013

Manual wheelchair propulsion can lead to pain and injuries of users due to mechanical inefficiency of wheelchair propulsion motion. The kinetic analysis of the upper limbs during manual wheelchair propulsion needs to be studied. A two dimensional inverse dynamic model of upper limbs was developed to compute the joint torque during manual wheelchair propulsion. The model was composed of three segments corresponding to upper arm, lower arm and hand. These segments connected in series by revolute joints constitute open chain mechanism in sagittal plane. The inverse dynamic method is based on Newton-Euler formalism. The model was applied to data collected in experiments. Kinematic data of upper limbs during wheelchair propulsion were obtained from three dimensional trajectories of markers collected by a motion capture system. Kinetic data as external forces applied on the hand were obtained from a dynamometer. The joint rotation angles and joint torques were computed using the inverse dynamic model. The developed model is for upper limbs biomechanics and can easily be extended to three dimensional dynamic model.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.26 no.4
• /
• pp.419-432
• /
• 2010

Various torque generating devices have been developed and employed to apply a proper torque. These devices are usually calibrated by the manufacturer to apply appropriate torque levels for their specific implants and attachments. The purpose of this investigation was to determine and compare the accuracy of the torque controllers. In this study, 4 types of torque controllers were used; torque limiting device(TLD), torque indicating device(TID) and contra angle torque driver(CA), electronic torque controller(ETC). Digital torque gauge was employed to measure the de-torque value. Thirty cycles of tightening and loosening were repeated with each torque controller. All implant torque controllers have shown slight errors and deviations. The contra angle torque driver exhibited the most accurate data. In the limitation of this study, it would be recommended that the implant torque controllers should be checked whether uniformed and precise torque can be generated and a measuring error should be corrected.

• Journal of the KSME
• /
• v.31 no.1
• /
• pp.51-59
• /
• 1991

본 글에서는 일반적인 공간 매니퓰레이터에 관한 가속도 이론을 서술하였다. 즉, 주어진 매 니퓰레이터에 대하여 액튜에이텨 토크집합 T에 대한 치역 $S_t$와 관절변수변화율집합 F에 대한 지역 $S_q$를 정의하였다. 또한 상태공간에서의 한 점 u에서의 상태가속도 집합 $S_u$를 정의하였다. 치역 $S_t$를 결정하고 그 성질인 최대가속도와 동방가속도를 결정하였다. 아울러, 가속도이론의 하나의 적용례로서 정해진 동방기동가속도를 얻을 수 있는 최소한의 액튜에이터 토크의 크기를 결정하는 방법을 도시하였다. 본 결과의 다양한 응용예는 기존연구를 참조하기 바란다.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.6
• /
• pp.670-677
• /
• 2011

This study is to estimate the joint torques without torque sensor using the EMG (Electromyogram) signal of agonist/antagonist muscle with Neural Network Back Propagation Algorithm during the elbow motion. Command Signal can be guessed by EMG signal. But it cannot calculate the joint torque. There are many kinds of field utilizing Back Propagation Learning Method. It is generally used as a virtual sensor estimated physical information in the system functioning through the sensor. In this study applied the algorithm to obtain the virtual senor values estimated joint torque. During various elbow movement (Biceps isometric contraction, Biceps/Triceps Concentric Contraction (isotonic), Biceps/Triceps Concentric Contraction/Eccentric Contraction (isokinetic)), exact joint torque was measured by KINCOM equipment. It is input to the (BP)algorithm with EMG signal simultaneously and have trained in a variety of situations. As a result, Only using the EMG sensor, this study distinguished a variety of elbow motion and verified a virtual torque value which is approximately(about 90%) the same as joint torque measured by KINCOM equipment.