Current Issue : July - September Volume : 2014 Issue Number : 3 Articles : 6 Articles
Stress signal is difficult to obtain in the health monitoring of multibody manipulator. In order to solve this problem, a soft sensor\nmethod is presented. In the method, stress signal is considered as dominant variable and angle signal is regarded as auxiliary\nvariable. By establishing the mathematical relationship between them, a soft sensor model is proposed. In the model, the stress\ninformation can be deduced by angle information which can be easily measured for such structures by experiments. Finally, test of\nground and wall working conditions is done on a multibody manipulator test rig. The results show that the stress calculated by the\nproposed method is closed to the test one.Thus, the stress signal is easier to get than the traditional method. All of these prove that\nthe model is correct and the method is feasible....
Two mechatronics prototypes, useful for robotic neurotreatments and new clinical trainings, are here presented. P.I.G.R.O.\n(pneumatic interactive gait rehabilitation orthosis) is an active exoskeletonwith an electropneumatic control. It imposesmovements\non lower limbs in order to produce in the patient�s brain proper motor cortex activation. Bra.Di.P.O. (brain discovery pneumatic\northosis) is anMR-compatible device, designed to improve fMRI (functional magnetic resonance imaging) analysis.Thetwo devices\nare presented together because both are involved in the study of new robotic treatments of patients affected by ictus or brain stroke\nor in some motor learning experimental investigations carried out on healthy subjects....
Physiologically and biomechanically, the human body represents a complicated system with an abundance of degrees of freedom\n(DOF). When developing mathematical representations of the body, a researcher has to decide on how many of those DOF to\ninclude in the model. Though accuracy can be enhanced at the cost of complexity by including more DOF, their necessity must\nbe rigorously examined. In this study a planar seven-segment human body walking model with single DOF joints was developed.\nA reference point was added to the model to track the bodyââ?¬â?¢s global position while moving. Due to the kinematic instability of\nthe pelvis, the top of the head was selected as the reference point, which also assimilates the vestibular sensor position. Inverse\ndynamics methods were used to formulate and solve the equations of motion based on Newton-Euler formulae. The torques and\nground reaction forces generated by the planar model during a regular gait cycle were compared with similar results from a more\ncomplex three-dimensional OpenSim model with muscles, which resulted in correlation errors in the range of 0.9ââ?¬â??0.98. The close\ncomparison between the two torque outputs supports the use of planar models in gait studies....
Astudy of the inverse kinematics for a five-degree-of-freedom(DOF) spatial parallel micromanipulator is presented here below.The\nobjective of this paper is the introduction of a structural and geometrical model of a novel five-degree-of-freedom spatial parallel\nmicromanipulator, analysis of the effective and useful workspace of the micromechanism, presentation of the obtained analytical\nsolutions of the microrobot�s inverse kinematics tasks, and verification of its correctness using selected computer programs and\ncomputation environments. The mathematical model presented in this paper describes the behaviour of individual elements for\nthe applied 2-DOF novel piezoelectric actuator, resulting from the position and orientation of the microrobot�s moving platform....
Compared with conventional mechanisms, tensegrity mechanisms have many attractive characteristics such as light weight, high\nratio of strength to weight, and accuracy of modeling. In this paper, the kinematics, singularity, and workspaces of a planar 4-\nbar tensegrity mechanism have been investigated. Firstly, the analytical solutions to the forward and inverse kinematic problems\nare found by using an energy based method. Secondly, the definition of a tensegrity mechanism�s Jacobian is introduced. As a\nconsequence, the singularity analysis of the planar 4-bar tensegrity mechanism has been completed. Thirdly, the actuator and\noutput workspaces are mapped. Finally, some attractive characteristics of the mechanism are concluded....
A current trend in robotics is fusing different types of sensors having different characteristics to improve the performance of a\nrobot system and also benefit from the reduced cost of sensors. One type of robot that requires sensor fusion for its application\nis the service robot. To achieve better performance, several service robots are preferred to work together, and, hence, this paper\nconcentrates on swarm service robots. Swarm service mobile robots operating within a fixed area need to cope with dynamic\nchanges in the environment, and they must also be capable of avoiding dynamic and static obstacles. This study applies sensor\nfusion and swarm concept for service mobile robots in human services and rehabilitation environment. The swarm robots follow\nthe humanmoving trajectory to provide support to humanmoving and performseveral tasks required in their living environment.\nThis study applies a reference control and proportional-integral (PI) control for the obstacle avoidance function. Various computer\nsimulations are performed to verify the effectiveness of the proposed method....
Loading....