In this research, we focus on the method of rehabilitation with stretch reflexes for the hemiplegic upper limb in stroke patients. We propose a new device which utilizes electromagnetic force to evoke stretch reflexes. The device can exert an assisting force safely, because the electromagnetic force is non contact force. In this paper, we develop a support system applying the proposed device for the functional recovery training of the hemiplegic upper limb. The results obtained from several clinical tests with and without our support system are compared. Then we discuss the validity of our support system.

In this research, we focus on the method of rehabilitation with stretch reflexes for the hemiplegic upper limb in stroke patients. We propose a new device which utilizes electromagnetic force to evoke stretch reflexes. The device can exert an assisting force safely, because the electromagnetic force is non contact force. In this paper, we develop a support system applying the proposed device for the functional recovery training of the hemiplegic upper limb. The results obtained from several clinical tests with and without our support system are compared. Then we discuss the validity of our support system.

This paper proposes a Strain-Deformation Expansion Mechanism with Flexure Hinges for joint torque sensing. By the torque sensing mechanism, the small strain-deformation on a joint used for torque sensing can be expanded wihile the sensor stiffness will not be reduced but will be heightened. For the mechanism, a novel flexure hinge with two overlap semicircular notches, where there are no friction and gap which are often existing in a rotational hinge, is proposed for preforming hign-precision sensing. In this paper, the force sensing principle is addressed by analyzing the deformation of the sensing mechanism and the forces acting on the sensor theoretically. Then, the sensitivity of the sensing mechanism are defined, and a design method for realizing the sensing mechanism with high sensitivity is discussed. Lastly, some experiments with robot finger are performed to show the basic characteristics and the effectiveness of the proposed joint torque sensing mechanism.

In this research, we propose a scheme to design the control system of a small unmanned rotorcraft flying in ground effect. Several H∞ controllers can be designed to stabilize the rotorcraft at desired altitudes respectively. However, one of these controllers can stabilize the rotorcraft only in the corresponding region limited small. We introduce several domains of attraction in the state space of the control system concerning the H∞ controllers. In order to perform the altitude control of the rotorcraft flying in various altitudes near ground, we present a switching control law with these H∞ controllers and domains of attraction. The feasibility of the presented scheme is verified through several experiments.

In our research, we consider of applying the swing of human's arms to the mechanical elements of a jumping machine. We call such a jumping machine 'Pendulum-type Jumping Machine'. In this paper, a pendulum-type jumping machine which consists of three links and two motors is constructed. One of three links is treated as the body of the jumping machine and the others are treated as its arms. The jumping machine can jump up to a step by swinging arms cooperatively. We introduce the scheme of soft landing so that the jumping machine can land on the step without tumble. The posture control problem of a free-flying system is explored to achieve the soft landing by the jumping machine. Then the ability of ascending stairs by the jumping machine is demonstrated through experiments.

In order to grasp and manipulate an object controllably and dexterously with a multifingered hand of robot, the sensing of fingertip force is required. To these operation, for making the controlability higher and making force sensor be proof against unexpected collisions or weights, not only the sensor’s sensibility but also its stiffness are desired as high as possible. For sensing a force acting on a force sensor, in general, some sensing elastic bodies is equipped in the force sensor. When a force is applied on the sensor, the force will pass through the sensing elastic bodies and make the bodies deform linearly so that it can be measured from the strain-deformations on the elastic bodies. So far, many researches [1]∼[7] [9] consider making the sensed force all passed through the sensing elastic bodies for force sensing. To this situation, if we want to make the sensibility higher, the stiffness of the sensing elastic bodies have to be reduced for making their deformations larger. Conversely, if we wan to make the stiffness higher, the sensibility of the sensing elastic bodies will be reduced since their deformations become to small because of the higher stiffness. Thus by using the previous sensing structures, it is hard to realize the force sensing with both of high-stiffness and high-sensitivity. For instance, about torque sensing, some strain gauges are put on an arm joint shaft to sense the torque deformation on the shaft [1]. In this way, to make the sensitivity higher, reducing the stiffness of joint shaft, for instance, using an elastic shaft as a portion of joint shaft [2], was considered. On the other hand, a joint shaft and an arm link was fixedly connected in series by an elastic body and its elastic deformation was used for joint torque sensing [3]. However this method will reduce the joint stiffness, too. Also, double-cross structure [7], double-membrane structure [6] [8] were proposed for force sensing or acceleration sensing. But these methods will reduce the sensor’s stiffness if higher sensibility is required. In general, increasing the sensitivity of joint torque sensing by reducing the joint stiffness, is not desired. This paper proposes a novel mechanism called Strain-Deformation Expansion Mechanism for 3-axis force sensing. By the force sensing mechanism, the small strain-deformation used for force sensing can be expanded while the sensor stiffness will not be reduced but will be heightened. In this paper, the force sensing principle is addressed by analyzing the O pe n A cc es s D at ab as e w w w .in te ch w eb .o rg

In this paper, a remote control mechanism for the crawler-type robot by use of flexible shafts is proposed. Since the robot does not have to mount any power unit for the locomotion on the body, the weight of the robot can be lightened and it can mount other devices alternatively. Furthermore, since the electric power is not used to the mobile mechanism on the body, the danger of fire is extremely low even if it performs rescue operation in collapsed building with gas leakage. To construct the proposed mobile mechanism, we devise the structure of the flexible shafts. We make up an experimental crawler-type robot which is composed of the proposed mechanism. Then the feasibility of the remote control system with the proposed mechanism is demonstrated by several experiments.

This research considers a human-limb power assist system, which can feedback the power- damped operating forces to human. The system can easily suitable to a person without using EMG sensor and knowing limb's mass, viscosity and elasticity. The control method, assist rate and system unit are discussed in this paper. Lastly, experimental verification on the proposed approach is performed and its results are outlined.

This paper develops a 3-DOF active rotational ball joint with a simple and compact mechanism, which can realize a rotation around an any- direction rotational axis with a well manipulability and can change its direction of rotational axis smoothly and arbitrarily when it is on rotating. The mechanism principle of this joint is proposed and analyzed. Then the ball joint is developed and experimental verification on the proposed mechanism is performed. The effectiveness of the mechanism principle is outlined by some experimental results.

In order to perform an assembly operation by robot successfully, it is necessary to estimate the correct position and geometric information of a fixed environment. This paper describes a technique that can estimate the contact position and geometric information between a quadric object and a quadric environment from a number of positions and orientations of a moving object, which are measured while the object is dexterously slid and rotated on the environment around the contact position. There are six kinds of basic contact forms when the two quadric bodies are in contact with each other. Corresponding to four of these basic contact forms, four kinds of estimation approaches are proposed. By these estimation approaches, the environment position and geometric information on contacting parts can be estimated successfully. Experimental verification on the proposed approaches is performed and its results are outlined

In this report, we consider a problem of motion control of an inverted pendulum cart which moves along a sloping track with nonlinear characteristics. We design LQ state feedback gains around several equilibrium points. Then we calculate regions which have them in asymptotically stable. We propose the switching control system by use of LQ state feedback gains in consideration of their regions. Through numerical simulation, we investigate the feasibility of our control system which can perform a motion control of the inverted pendulum cart and which is robust against some disturbances while it moves.

In this research, a remote control mechanism for the crawler-type robot by use of flexible shafts is proposed. Since the robot does not have to mount any power unit for the locomotion on the body, the weight of the robot can be lightened and it can mount other devices alternatively. Furthermore, since the electric power is not used to the mobile mechanism on the body, the danger of fire is extremely low even if it performs rescue operation in collapsed building with gas leakage. In this report, we discuss the characteristics of the flexible shafts which are constructed for the mobile mechanism. Then we investigate the relation between the length of the flexible shaft and the traction ability of the mobile robot.

We used a computerized delayed-reaching task with a simple reaction time (RT) to investigate the visuo-motor and spatio-temporal performance of right brain-damaged (RBD) patients with unilateral spatial neglect (USN). Fifty-three RBD patients (22 with and 31 without USN) and 25 controls performed the tasks. We recorded the following data: the first RT (RT-1), which is thought to reflect the detection of the target position (the perceptual factor); the second RT (RT-2), which represents the initiation of reaching (the motor initiation aspect of premotor factors); the movement time (MT), which is hypothesized to reflect the "pure" motor component of the task. RBD patients with both USN and hemianopia demonstrated significantly longer RTs towards the left than towards the right for both the RT-1 and the RT-2. Among the RBD patients without hemianopia, the laterality index (left side/right side) of the RT-1 in those with USN was significantly greater than in those without USN or the controls. Among the three groups, there were no significant differences between the laterality indices of either the RT-2s or the MTs. These results suggest that the impairment of leftward movement in RBD patients with USN might be caused primarily by a perceptual impairment rather than an impairment in motor initiation, and is certainly not a "pure" motor impairment.

We have proposed an approach for deriving direct Jacobian of closed-loop parallel mechanism. In this paper, we discuss the kinematics analysis of closed-loop parallel mechanism based on the proposed direct Jacobian.

For dexterously performing object grasping and manipulation with multifingered hand of robot, sensing the fingertip forces with high-stiffness and high-sensitivity is desired. In general, from previous sensing structures, if the stiffness of a sensor is made be higher, its sensitivity is reduced. This paper proposes a novel mechanism called strain-deformation expansion mechanism for 3-axis force sensing. By the force sensing mechanism, the small strain-deformation used for force sensing can be expanded while the sensor stiffness is not reduced but is heightened. In this paper, the force sensing principle is addressed by analyzing the deformation of the sensing mechanism and the forces acting on the sensor theoretically. Then, the sensitivity of the sensing mechanism and its expansion rate of sensitivity are defined, and a design method for realizing the sensing mechanism with high sensitivity is discussed. Lastly, some experiments are performed to show the basic characteristics and the effectiveness of the sensing mechanism

This paper proposes a technique that can estimate the inertia parameters of a graspless unknown object, which is pushed by robot fingers. Using the fingertip different accelerations (or angular accelerations), velocities (or angular velocities) and forces information measured in pushing operations, the algorithms to estimate the object mass (or moment of inertia) are described. Then, a line called C.M. Line, is defined in this paper. The line contains the center of mass and is between two fingertips which are in point-contact with an object side. By using two or more than two orientation-different C.M. lines, an algorithm to estimate the center of mass of the object is given. Lastly, experimental verification on the proposed approach is performed and its results are outlined.

There are geometric and positional uncertainties in some operations such as assembly operations. In order to perform an assembly operation by robot successfully, it is required to estimate the correct geometric and position information of a fixed environment. This paper describes a technique that can estimate the contact geometric and position information between a quadric object and a quadric environment from a number of positions and orientations of a moving object, which are measured while the object is dexterously slid and rotated on the environment around the contact position. There are six kinds of basic contact forms when the two quadric bodies are in contact with each other. Corresponding to four of these basic contact forms, four kinds of estimation approaches are proposed. By these estimation approaches, the environment geometric and position information on contacting parts can be estimated successfully. Experimental verification on the proposed approaches is performed and its results are outlined.

The aim of this research is to investigate the new approach to the development of the system which supports inexperienced operators who are trying to acquire the machine operation skill. In this approach, we consider the support system which has the following functions; Firstly, the system works to lighten the burdens to the inexperienced operators, by using a controllable assist. Secondly, the system works to reduce gradually the effect of the assist according to the operator's skill. In this paper, we deal with an operation problem of a rotary arm with a pendulum and try to construct a support system for the acquisition of the operation skill. The number of trials required for the operation skill acquisition of the rotary arm is investigated. The results obtained from several experiments with our support system are compared with those without our support system. Then we discuss the validity of our support system.