Bruno Fausto Zappa

On the Number and Placement of Accelerometers for Angular Velocity and Acceleration Determination

This paper identifies the minimum number of accelerometers nec-essary to measure rigid body acceleration. Notwithstanding thatonly 9 scalar unknowns must be identified, 12 devices compose aminimum set of transducers. This redundancy is necessary toavoid singularities in the equations. Conditions for the sensorplacement are given. It is also shown that when the determinationof the angular velocity is not required, a reduced set of 9 sensorscan be adopted. @DOI: 10.1115/1.1386649#

Design and development of a Cartesian plotter as a way to teach Mechatronics to Mechanical Engineering students

The need for interdisciplinary skills in mechanics, electronics, control theory and computer science was recognized as becoming more and more important for mechanical designers. At this aim, it is since the academic year 2002/2003 that a course on Mechatronic Systems is delivered at Bergamo University as an option in the BS curriculum for mechanical engineering students. The course is mainly based on project oriented learning activities; actually a practical project is developed each year. This paper mainly deals with the description of the mechatronics education activity at Bergamo University, with reference to the 2005/2006 academic year course project: a Cartesian plotter driven by stepper motors

An Unified Design Procedure for Flying Machining Operations

One of the most important aspects of the design of “flying machining” operation is the choice of the proper law of motion of the slave axis. In literature, technical reports and papers can be found concerning this subject, but they deal with specific problems and the solutions or suggestions proposed are specific as well, suitable for those cases. In order to try to overcome this limitation, in this paper we analyze the subject of the flying machining operations from a wider point of view. We propose a unified design procedure that has general validity being suitable for the choice of the slave axis’ law of motion for whatever “flying machining” operation. Moreover the unified design process proposed includes also methodologies for the choice of motor and transmission.

Design of a fatigue ski testing bench

The aim of this paper is to show the design procedure for a fatigue ski test bench. The interest in developing an equipment to test ski characteristics has greatly raised since the introduction of carving skis. The characteristics of this kind of skis allow new trajectories and promise turn easiness and fun to everyone. These features come from a correct combination of ski shape and mechanical characteristics both of which determine load distribution under the edges. To quantify ski edge load and to characterise different skis, as well as to test their fatigue behaviour, we designed a ski test bench that allows to load an edged ski against an instrumented bed and to measure load distribution along the edge as well as the shape of the deformed edge.

Design of Torque Balancing Mechanisms

Machines are often subjected to periodic loads, related both to the characteristics of the payload or to the kinematic chains used for motion generation, such as linkages or cam follower mechanisms. The load fluctuation can cause several inconveniences to the proper functioning of the machines, like shaking forces and moments, vibrations, severe speed fluctuations. Speed fluctuations are a main source of concern since, generally, mechanisms design and optimization is performed considering a constant main shaft speed and a departure from ideal behavior gets worse increasing machine speed. The simpler approach used to mitigate this fact consists in adopting a large flywheel and/or a massive motor, even to drive small loads. More sophisticated procedures add appropriate balancer mechanisms to the machine. This paper, starting from a review of the available literature, presents a theoretical framework to the problem of input torque balancing and defines a methodology for the synthesis of balancing mechanisms.

Design and Optimization of a PKM for Micromanipulation

The actual miniaturization trend, present in several industrial sectors, requires high performance capabilities in micromanipulation and assembly. A complete automation of these operations, by means of robots, could result in a significant cost cut in the final product. In this work we present the mechatronic design and optimization of a 3 d.o.f. Delta type PKM for micromanipulation. Starting from a reference task (pick and place with high stroke rate) the optimal links length has been determined by considering several kinematic performance indexes; afterwards the actual link sizing has been performed considering dynamic loading, also taking into account the effect of the links flexibility on end effector trajectory. A direct drive actuation has been chosen, where the motor sizing has been performed to satisfy several criteria: maximum and r.m.s. torque and maximum speed. The motor selection has been speeded up querying a database built by collecting data from the catalogues of several producer. Furthermore robot joints have been carefully designed in order to reduce backlash and friction.