Force Display System Research Articles

Design of an accurate end-of-arm force display system based on wearable arm gesture sensors and EMG sensors

Most upper limb rehabilitation patients are still hard to feel the accuracy force they have imposed in the end of arm after a systematic upper limb rehabilitation. In order to provide an accurate end-of-arm force for those disabled people, a force display system based on wearable arm gesture sensors and Electromyographic (EMG) sensors is designed and given in this paper. The wearable arm gesture sensors and EMG sensors are specially placed to detect the arm gesture and the EMG signal of the arm, and a force sensor is used to measure the force and verify the force display effect. In order to control the rehabilitation arm move slowly at a constant speed, the kinematic model of the upper arm is analyzed. A special experiment platform is established so as to get the simultaneous data of end-of-arm force and the arm gesture and EMG signal, then the Generalized Regression Neural Network (GRNN) is brought in to catch the relationship between them. A group of horizontal movement experiment and vertical movement experiment are designed specially and verify the feasibility and effectiveness of the system. The result shows that the information fusion based on GRNN for this system could accurately display the end-of-arm force.

シリアルリンク機構/パラレルワイヤ駆動システムによる力覚呈示装置の開発( 遠隔操作システム)

シリアルリンク機構/パラレルワイヤ駆動システムによる力覚呈示装置の開発( 遠隔操作システム)

計測反力データ群の補間に基づく3次元反力表示システム(「ハプティックインタラクション」特集)

計測反力データ群の補間に基づく3次元反力表示システム(「ハプティックインタラクション」特集)

Stiffness Display by Muscle Contraction Via Electric Muscle Stimulation

Although electrical muscle stimulation (EMS) has been used in various haptic interfaces, haptic sense induced by EMS does not satisfactorily provide the full spectrum of haptic events. It is difficult to convey certain haptic sensations accurately through EMS. In this study, we aim to create the haptic sensation of the stiffness of an object by using muscle contraction induced by EMS. To simulate varying degrees of stiffness or elasticity of different objects, we must vary the displayed force depending on the displacement. To generate a haptic sensation corresponding to the force applied on the hand, we measure the generated force at the hand when electric stimulation is applied to a particular muscle. Once we have a model of the relationship between the applied electric stimulation and the generated force, we can determine the intensity of the electric stimulation required to simulate the target stiffness. In this study, we develop a haptic force display system that renders different levels of stiffness using EMS. We analyze the performance of our system by measuring the perceived stiffness in human experiments. The experimental results show a positive correlation between the target stiffness and perceived stiffness.

2A1-A05 力覚提示システムを定量的に評価する基盤的アプリケーションの開発

2A1-A05 力覚提示システムを定量的に評価する基盤的アプリケーションの開発

213 全方向駆動歯車を利用した力覚提示装置の開発(メカトロニクス)

213 全方向駆動歯車を利用した力覚提示装置の開発(メカトロニクス)

Pseudo Force Display that Applies Pressure to the Forearms

Conventional force display systems provide a force sensation by applying force to the operator's body via actuators such as electric motors. These systems can potentially harm the operator, especially when providing a large force sensation. This study shows that constrictive pressure on the distal part of the forearms provides a force sensation such as holding a heavy object or pushing a wall when the pressure changes in accordance with the hand motion. This force display provides a large force sensation of ∼10 N without applying real force to the operator's hand, which makes the system intrinsically safe and suitable as a wearable force display system. Experimental results show that the discrimination thresholds are consistent with Weber's Law. It was demonstrated that an operator could sort virtual objects by weight using this system.

Analysis of Facial Expressions during Muscle Strain Using a HMD-Based Virtual Arm Wrestling System Designed for Facial Electromyography Measurement

In this study, we analyze physiological information of facial electromyography and respiration using a force display system of a virtual arm wrestling system. We found that facial expressions under transient cessation of respiration during muscle strain are characterized by tension of the corrugator supercilii and zygomaticus major muscles. In addition, facial expressions of laughter, anger, and fear, and those during muscle strain can be distinguished based on the active pattern of the corrugator supercilii and zygomaticus major muscles. These findings are useful in the evaluation of emotions based on facial expressions during muscle strain using a head mounted display (HMD)-based virtual reality system.

Basic Research of “MR-PLEMO”: 2-D Passive-Type Rehabilitation System for Upper Limbs Using MR Fluid Brake

Rehabilitation for the upper limbs is important for elderly people, people who have suffered strokes, and so on. In recent years, the need for rehabilitation support systems is increasing that use force display systems. When using a force display system, it is most important to ensure safety mechanically in order to prevent operators from hurting subjects. Conventional force display systems are active systems with actuators and these systems may become dangerous when going out of control. Passive force display systems with only passive elements are, however, thought to be an effective method for assuring inherent safety. In this paper, we evaluate force display ability for a 2-D passive-type force display system using fast-response MR (Magneto-Rheological) fluid brakes in order to apply this system to rehabilitation training.

2-D Force Display System with Redundant ER Fluid Brake Aimed at Rehabilitation Support System for Upper Limbs

These days, there aremany patients with ataxia, which is paralysis caused by a brain stroke or asynergia. Early detection of functional deterioration and sufficient rehabilitative training are necessary for these patients. Rehabilitation support systems for upper limbs using force display systems are expected to quantify the effects of rehabilitative training and enhance the motivation of patients. The application of a passivetype force display system is especially desirable for its high safety. There are, however, some directions and positions for which it is difficult to display force in a passive-type force display systemusing only passive elements. To solve this problem, a method for the improvement of controllability using redundant brakes had been suggested. This method made it possible to display more various force power and directions than could be done with previous systems. In this study, we have developed a redundant-brake rehabilitation system for the upper limbs: Redundant-PLEMO-1.

Development of the Passive-Type Force Display System ”Neo-PLEMO”, Which Can Display the Opposite Resistance Force against Handle on the Arbitrary Link Posture

Rehabilitation for upper limbs is important for elderly people, people who have suffered a stroke and so on. In recent years, the needs for rehabilitation support systems are increasing, which use force display system. Especially, the application of a passive-type force display system is desirable for its high safety. However, there are some directions and link positions for which it is difficult to display the force in a passive-type force display system using only passive elements. To solve this problem, a method for improvement of controllability using redundant brakes had been suggested. This method made it possible to display various force directions and various postures of virtual objects. However, the system with redundant brakes has the problem that it often become huge system. In this paper, we develop the new system which can display the opposite resistance force against handle on the arbitrary link posture. This system use only two ER fluid brakes for force generation, so become compact. Moreover, we perform basic experiment in order to verify this system.

E-2-4 錯覚を利用した力覚呈示のための圧覚特性調査(E-2 生体センサ・デバイス,口頭発表:生体治療・医療,バイオ操作・検査)

Grounded force-display systems generally suffer the difficulty of workspace restriction. On the other hand, if we utilize an illusion on a sense of contact force, a wearable non-grounded force display system would be developed much easier than without utilizing the illusion. We found an interesting phenomenon, i.e., a kind of illusion from an experiment using a prototype device: a majority of subjects perceive a biased force in either direction even though, facing each other on both sides of a forearm, two sets of external forces are applied to the forearm in equal strength. As for the factors of the phenomenon with the baresthesia, i.e., the sense of pressure, we considered the area effect and the adaptation one. In order to examine the mechanism of this phenomenon, we carried out some experiments to investigate fundamental characteristics with each of the factors. Then, we, furthermore, did some extended experiments where the both factors are mixed, and showed that the baresthesia is well explained by the fundamental characteristics.

1A2-E19 力覚提示を用いた上肢リハビリ支援装置EMULへの拡張現実技術の導入

The rehabilitation systems using force display system is useful for rehabilitation of upper limbs. However graphics displayed on a monitor of existing rehabilitation systems has a low level of visibility. Now to solve this problem, using Augmented Reality (AR)Technology has been suggested. AR will enhance a level of visibility and make it possible to measure joint angle like wrist angle which is important for rehabilitation of upper limbs. In addition, AR application for exercising bodily movement in diet has been developed.

1A2-F06 任意の手先位置・運動方向において逆向き抵抗力を提示可能な2次元パッシブ型上肢リハビリ支援システムの研究開発

In recent years, the number of stroke patients has been increasing. The rehabilitation systems for upper limbs using force display system are expected to quantify the effect of rehabilitative training, and can enhance the motivation of an operator. A passive-type force display system uses only brake, and ensures high safety. It can display resistance force by using brake. For this force, the system must display the force in the opposite direction. However, the system cannot display this opposite force in some cases. In this paper, we research the mechanism to display the opposite force to all motion direction at all posture. And we describe a rehabilitation system for upper limbs: NEO-PLEMO, which use this mechanism.

冗長個数のER流体ブレーキを用いた2次元上肢リハビリ支援装置に関する基礎研究 : 第1報,力覚提示能力に関する解析(機械力学,計測,自動制御)

Rehabilitation for upper limbs is important for elderly people, people who have suffered a stroke and so on. In recent years, the needs for rehabilitation support systems are increasing, which use force display system. Especially, the application of a passive-type force display system is desirable for its high safety. However, there are some directions and link positions for which it is difficult to display the force in a passive-type force display system using only passive elements. To solve this problem, a method for improvement of controllability using redundant brakes had been suggested. This method made it possible to display various force directions and various postures of virtual objects. In this paper, we research about force display ability of passive-type system with redundant brakes.

1A2-E22 パッシブ型上肢リハビリ支援システムのための新型MR流体ブレーキ開発に関する基礎研究

In recent years, the number of stroke patients has been increasing. The rehabilitation systems for upper limbs using force display system are expected to quantify the effect of rehabilitative training, and can enhance the motivation of an operator. A passive-type force display system uses only brake, and ensures high safety. It can display resistance force by using brake. Magneto-Rheological fluid (MRF) is one of the functional fluid and its rheological properties can be controlled by applying magnetic field. So, MRf Brake has good responsibility and high torque. In this paper, we describe development of New type MRf Brake which is cpable of generating High Torque by only one disk which is holed like a ring and its magnetic field analysis by ANSYS

Fundamental Research about a 2-D Passive-type Force Display System Using MR Fluid Brake

Fundamental Research about a 2-D Passive-type Force Display System Using MR Fluid Brake

低電圧駆動ＥＲ流体ブレーキを冗長個数用いた２次元力覚提示システムの研究開発

Passive-type force display systems have the merit of high safty, but there are some directions and link positions for which it is difficult to display the force by using only passive elements. To solve this problem, a method for improving the controllability by using redundant brakes had been proposed. This method, however, requires brakes with short response time; ER fluid brakes are suited for this purpose. In this paper, we develop a novel passive-type force display system with redundant brakes. We have developed new multi-cylinder ER fluid brakes which can be operated at relatively low voltage. For transmitting the force, a new linkage system is designed which does not require any belt-pully system. It has been demonstrated that this system can display forces in a wide direction by using our controlling algorithm. A potential application of this system to rehabilitation training is proposed.

冗長個数のブレーキを有する力覚提示システムに関する基礎研究（性能評価方法の提案及び衝突感覚の力覚提示）

The application of a passive-type force display system is desirable for its high safety. However, there are some directions and link positions for which it is difficult to display the force in a passive-type force display system using only passive elements. To solve this problem, a method for improvement of controllability using redundant brakes had been suggested. This method made it possible to display various force directions and various postures of virtual objects. In our study, two novel methods are presented for performance evaluation of a passive-type force display system with redundant brakes. Using these methods, we evaluate the performances of a 2-DOF passive-type force display system without redundant brakes, a passive system with one redundant brake and a passive system with two redundant brakes. In this paper, two novel performance evaluation methods for a passive-type force display system with redundant brakes are presented. The developed system is outlined and basic experiments with it discussed.

2P1-K10 冗長個数のERブレーキを用いた2次元パッシブ型力覚提示システムの研究開発

2P1-K10 冗長個数のERブレーキを用いた2次元パッシブ型力覚提示システムの研究開発