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This paper introduces the effectiveness of the body motion for the pace gait of vertical ladder climbing. The pace gait is a symmetrical motion of left side and right side to climb the ladder. As a previous work, we realized the vertical ladder climbing motion; however, it is not stable since the external disturbance is not considered. We add a body motion as an improvement. The external disturbance...
Parametric excitation walking is one of methods that realize a passive dynamic like walking on the level ground. In parametric excitation walking, up-and-down motion of the center of mass restores mechanical energy and sustainable gait is generated. Walking ability and walking performance strongly depend on the reference trajectory of the center of mass. In this paper, we propose an optimization method...
Variable stiffness actuation (VSA) devices are being used to jointly address the issues of safety and performance in physical human-robot interaction. With reference to the VSA-II prototype, we present a feedback linearization approach that allows the simultaneous decoupling and accurate tracking of motion and stiffness reference profiles. The operative condition that avoids control singularities...
Safe mobility of the disabled is one of the major reasons for the study of electric powered wheelchairs. To achieve absolute safety - where possible accident is not attributed to by the user's inability, the wheelchair should be as easy as possible to control in nearly every kind of environment. A reliable controller can only be designed from a reliable dynamic model. In this paper, consider a 3D...
In this article a novel concept for specification of spatial paths for mechanism and kinematic design applications is presented. Mechanism designers use e.g. sketches for specification of motion curves. If these are created based on oral description, misunderstanding or inadequate formulation are sources of error. Further, it is difficult to generate them for spatial problems. The presented approach...
In this paper we consider the motion planning and control problem of an underactuated 3DOF rigid body. The dynamics of a particular experimental setup as abstraction of the rotational degrees of freedom of a helicopter is studied. The virtual holonomic constraints approach serves as analytical tool to plan various periodic motions of the system, where a synchronization pattern among the generalized...
We have already formulated a new optimal control model of the human three-joint arm system characterized by its hand-joint's freezing mechanism, and clarified that this model has the ability to explain the experimental fact that the hand joint hardly changes its angle in human three-joint arm's unconstrained reaching movements. However, it is not verified whether the three-joint model has the ability...
A new positioning system has been developed to realize both the fine motion and the coarse motion independently and/or simultaneously to reduce the positioning time under the limitation of guaranteeing the positioning accuracy. To cope with this problem, the conventional reducer unit driven by AC servomotor is utilized. The fine-coarse motion of the developed mechanism is realized by only mechanical...
This paper aims at generating desired feedforward torque for a specified motion by reuse of time-series torque data acquired by the iterative learning control. The suggested method named motion-scale transformation realizes a motion to an arbitrarily specified posture of a two-DOF planar robot arm on the basis of arithmetical operations of time-series torque of only four motions. The algorism is theoretically...
Cogging effect is a serious disadvantage of the permanent magnetic synchronous motor (PMSM), and cogging force is a position-dependent periodic disturbance. In our previous work [1], a dual high-order periodic adaptive learning compensation (DHO-PALC) method for state-dependent periodic disturbance was presented, where the long term stability issue was not addressed. Due to the impact of the high...
In the framework of physical human-robot interaction (pHRI), methodologies and experimental tests are presented for the problem of detecting and reacting to collisions between a robot manipulator and a human being. Using a lightweight robot that was especially designed for interactive and cooperative tasks, we show how reactive control strategies can significantly contribute to ensuring safety to...
The paper deals with development and realisation of the motion control for a very precise mechanism of a rocking knife driven by an electrical drive. The rocking knife provides transversal cutting of a moving steel strip into flat sheets of various, adjustable lengths. After development of mathematical model of the controlled mechanism there is designed the trajectory of the mechanism and based on...
The present paper proposes the control algorithm of direction of the end-point position error caused by the disturbance. Taking consideration of it, the effect of the disturbance on the end-point position is maximized in the direction of the singular vector corresponding to the maximum singular value. Therefore, if we can control the direction of the singular vector, we will be able to control the...
Tuning the control parameters of the feed drives for existing state of the art CNC machine tools, or retrofitting obsolete machine tools requires a close understanding of the position control process. The use of a mathematical model of the feed drive, combined with a computer simulation process is needed in order to fulfill the above mentioned tasks. In this paper some simulation tools for studying...
The real-time torque calculation and dynamic modeling have been the difficulties in the motion control of the permanent magnet spherical stepper motor. Based on the presented continuous trajectory tracking control mode, a simplified torque calculation method and the non-linear system dynamic model have been proposed. The perturbation of the system parameters, the model error and the external disturbance...
Human bipedal models behave symmetrically as well as asymmetrically depending upon nature of movement, task and orientation of the body. A bipedal model with full symmetry of limbs and movement is very redundant engineering design which has lots of unstable eigenvalues and poles. To avoid redundancy asymmetry is introduced which imposes coordination and controller design problem. In this paper, we...
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