Giovanni Incerti

Estimation Of The Dynamic Effect In The Lifting Operations Of A Boom Crane.

This paper describes a model for the study of the dynamic behavior of lifting equipments. The model here proposed allows to evaluate the fluctuations of the load arising from the elasticity of the rope and from the type of the motion command imposed by the winch. A calculation software was developed in order to determine the actual acceleration of the lifted mass and the dynamic overload inside the rope during the lifting phase. In the final part of the article an application example is presented, with the aim of showing the correlation between the magnitude of the stress and the type of the employed motion command.

Dynamic modelling of cam indexers driven by DC servomotors

Dynamic equations of the intermittent motion of an indexing mechanism are derived in this paper. The vibrations due to the compliance of the mechanical components and the backlash effect of the gear speed reducer coupled to the mechanism are studied by means of a lumped parameters model of the system. Besides the non-rigid behaviour of the device, the computer simulations consider also the effects related to the electromagnetic behaviour of the motor and to the velocity controller. The numerical results, presented and discussed in the paper, indicate that the proposed model is feasible to foresee the dynamic behaviour of an actual system

A Characterization of Cam Transmissions Through an Identification of Lumped Parameters

In this paper, a numerical-experimental procedure is proposed for an identification of parameters in cam transmissions. Models with lumped parameters are defined specifically for cam transmissions. Experimental tests are carried out on main components of a cam transmission in order to estimate the values of mass, damping and stiffness lumped parameters through a low-cost easy-operation procedure. Experimental tests are also carried out in order to characterize the dynamic behaviour of a whole cam transmission. A comparison of numerical and experimental results is used in order to calibrate the values of lumped parameters. Experimental tests have been carried out by means of suitable test-beds for cams that have been built specifically at University of Brescia and at LARM in Cassino as alternative testing solutions.Copyright

Dynamic Analysis of Handcycling: Mathematical Modelling and Experimental Tests

The handbike is an upper body-powered vehicle used for sports and rehabilitation purposes. The advantages include improving patients physical activities and fitness level, as well as promoting an active lifestyle after rehabilitation duration. In this research the torques in shoulder and elbow joints have been determined during handbike motion from dynamic output and kinematics information. Therefore, a 2D model was presented. Data have been collected based on the output of experimental results obtained by sensors inserted on the handles of a cycle ergometer and by marker coordinates acquired by a vision system.

Dynamic behaviour of elastic cam devices driven by servomotors with PID velocity control

A mathematical model for dynamic analysis of elastic cam devices driven by DC motors with velocity control is presented in this paper. Besides the dynamic modelling of the cam system, the model considers the electromagnetic behaviour of the motor and the response of the speed regulator, based on a standard PID (proportional, integral and derivative) algorithm. The proposed model can be used as design tool, to simulate actual cam servomechanisms with a good degree of reliability and to evaluate the effects due to a modification of the control system parameters. Some simulation results are included in the paper, to demonstrate the possibility of use of the model.

A Technique for Vibration Suppression of a 2 DOF Compliant Manipulator

The paper describes a motion planning method that is able to reduce the vibrations of robots having non-rigid transmissions. The proposed approach is based on the use of parametric motion laws (for each axis of the machine) derived from standard polynomial functions. The parameters that define the shape of the motion profiles are selected in such a way as to reduce the so called “overshooting effect”, that is the mechanical vibration arising at the end of the motion time. The calculation procedure employs a mathematical model of the manipulator and an optimization algorithm, that acts as a motion planner and automatically selects the acceleration profiles of the robot actuators.

Vibration control of a SCARA manipulator using pseudo-polynomial motion laws

The paper describes a motion planning procedure aimed to vibration control of industrial robots for assembly operations. The proposed technique is based on a ldquopre-shapingrdquo of the motion profiles assigned to each degree of freedom of the machine. A mathematical model is used to simulate the dynamic behaviour of the manipulator and an optimization procedure, based on mathematical programming techniques, is employed for the automatic selection of the motion laws that allow vibration reduction. Some numerical results are presented in the final part of the paper, in order to demonstrate the effectiveness of the proposed approach.