a new mechanical cultivator was proposed for mechanical weeding in part one. the precise point method was used to geometric design of this new cultivator. the aim of this research is selecting the suitable mechanism of the studied mechanisms in part one. the velocity and acceleration of links (kinematic) is the base of dynamic analysis of the systems. the variation of velocity, acceleration and...

BACKGROUND The purpose of this study was to investigate the lifting characteristics of elders with functional limitations using burden lifting smoothness, trunk angular momentum, and back and hip torque, and to correlate these characteristics with strength and functional measures. METHODS Thirty elders (65-89 years old) consented to biomechanical analysis of lifting, gait, and chair rise, and...

A novel approach based on genetic algorithms (GA) is developed to find a global minimum-jerk trajectory of a space robotic manipulator in joint space. The jerk, the third derivative of position of desired joint trajectory, adversely affects the efficiency of the control algorithms and stabilization of whole space robot system and therefore should be minimized. On the other hand, the importance ...

In this work, we propose a convenient method for evaluating levels of angular jerk in augmented reality (AR) and virtual (VR). Jerk is rarely analyzed metric usability studies, although it can be measured calculated easily with most head-worn displays yield highly relevant information to designers. Here, developed implemented system capable calculating analyzing real-time based on orientation d...

On the circular curve, lateral acceleration affects comfort. On the spiral, both lateral acceleration and jerk affect comfort.  The determination of maximum curving speed on the basis of lateral acceleration only is not critical because the lateral acceleration is proportional to the square of speed whereas jerk is proportional to cubic power of speed. The maximum speed on a curve is thus signi...

on the circular curve, lateral acceleration affects comfort. on the spiral, both lateral acceleration and jerk affect comfort.  the determination of maximum curving speed on the basis of lateral acceleration only is not critical because the lateral acceleration is proportional to the square of speed whereas jerk is proportional to cubic power of speed. the maximum speed on a curve is thus signi...

One of the interesting properties of curved hand movements is that the speed v is related to the curvature k through a power law: v(t) ∝ k(t)-1/3 , called the ⅔ power law (because the angular speed is proportional to k 2/3). Several models have been proposed to explain the origin of the ⅔ power law from optimality principle: the minimum jerk models to name a few. It seemed the ⅔ power law was a...

This paper presents a method for path-following for quadcopter trajectories in real time. Non-Linear Guidance Logic is used to find the intercepts of the subsequent destination. Trajectory tracking is implemented by formulating the trajectory of the quadcopter using its jerk, in discrete time, and then solving a convex optimization problem on each decoupled axis. Based on the maximum possible t...

The method of jerk-locked back averaging was applied to six patients with clinically diagnosed psychogenic myoclonus. Five patients had a slow negative EEG shift corresponding to Bereitschaftspotential at the central region starting 0.7 to 2.1 seconds before the onset of the myoclonic jerk. One patient had no potential preceding the myoclonic jerk, whereas a small negative potential preceded th...

In this paper the problem of variable admittance control in human-robot cooperation tasks is investigated, considering rotational motion of the robot’s end-effector. A Fuzzy Model Reference Learning algorithm is used to determine online the appropriate virtual damping of the admittance controller with partial state representation of the system. The learning algorithm is trained according to the...