The state of the Union

Yesterday we had a design review of the RUMBy project. I will post here the links to PDF versions of the presentation. Until now, the first two presentations are available, but keep an eye on this post, because more will follow on.

• Introduction by F. Biral
• Architecture by P. Bosetti

Matteo Grott is a PhD student

This activity mainly consist in the design of controlled suspension systems for innovative heavy duty vehicles. Generally, the roles of suspension systems are ride comfort and handling. For off-highway vehicles there are other significant requirements such as the adaptation of the vehicle height, the minimization of the suspension working space and the reduction of the infrastructure damage. For heavy-duty vehicles, the working conditions (load and operative conditions, road types, etc.) can vary considerably and have an effect on the dynamical behaviour of the vehicle. Moreover, in many cases (such as tractors), only the front axle is provided with a suspension. A passive suspension could hardly satisfy all these conflicting requirements. Consequently, the employment of a controllable suspension is a potential way to reach the desired dynamical performance. As a matter of fact, the largest manufacturers of agricultural equipment are looking for solutions to control suspension stiffness and damping (widely used in the automotive industry). Among the many different types of controlled suspensions, the semiactive ones seem to be the best compromise between cost and performance: they only require shock-absorbers with controllable damping coefficients. On the other hand, the main limit of semiactive suspensions is the ”passivity constraint”: it is impossible to deliver vertical forces on the body having the same direction of the suspension elongation speed. This kind of system is classified as ”bilinear” to which the linear control theory cannot be applied. Commercial applications in off-highway industry include the suspension of the cabin (known as secondary suspension system) and the front axle (known as primary suspension system). As new solutions for secondary systems have been developed, improvements in performance have been reached. The primary systems are generally implemented with passive systems, due to economical motivations and their limited energy demand. Obviously, such technical solution partially satisfies the system requirements. The main goal of my research activity is the design of a cost-effective controlled suspension for a primary system, capable to adapt the dynamical behaviour of an agricultural tractor under different road and load conditions. Above all, I am evaluating the application of suspension system technologies currently used for light commercial vehicles to off-highway vehicles. Some examples of these technologies are active and semi-active suspension systems and different mechanical configurations.

Omar Daud is another Ph.D. student. Here is his current work.

For a long time medical research has been searching solutions for the attenuation of the dramatic consequences of cerebrovascular accidents. For this reason, there are many researchers from different fields that are working on this problem. Approximately 14% of the world’s population suffers strokes. This is the main cause of disability today. Two thirds of the patients that survive are left with some disability. It is not only strokes that damage the motor and sensory system, but also other pathologies. For a person who has suffered a stroke it is fundamental to regain at least the capability of using their hand. Many studies attest that initiating physical therapy immediately after a stroke grants a higher quality of life for the patient. The use of virtual reality with the support of haptic devices is a new approach for treating this disability. A haptic interface is a device that enables a manipulator to move and to interact with virtual objects within a virtual space. Due to this interaction the user receives a force feedback as a response. This permits the user to interact virtually with various types of objects that may have different properties, depending on the settings. In addition, these objects can move in the virtual workspace and create virtual animations in which the user may have the opportunity to exercise in a dynamic way. The patient may also use other interfaces connected with other virtual worlds. For a post-stroke patient, this type of therapy highly contributes to regaining the mobility of the hand. As a result, the use of haptic interfaces has the potential to rehabilitate and help stroke survivors relearn skills that were lost when part of the brain was damaged.

Giordano Miori is a Ph.D. student. Here is some excerpt from his current work.

Roundness and Spindle Radial Error Motion Measurement

Student: Giordano Miori Tutor: Mariolino De Cecco

The project “roundness and spindle radial error motion measurement” foresees the development of an innovative system in order to measure the shape, the axis deviation and motion of large cylinders. More precisely the project aims to improve the measurement accuracy by using more than three sensors and by implementing a newer reconstruction algorithm. This goals needs the modelization of the entire measurement system in order to carry out the simulations of the measurement process necessary for developing and testing the algorithm. Moreover the realization of a prototype of the multipoint measurement system is in the works. My own activity is the modelization of the measurement system and the cylinder as well as the development of the multi-point reconstruction algorithm. The first step of the work was been the modellization of a cross section of the cylinder. More precisely the mathematical representation of its the shape and of the motion of the geometric center of the section during the rotation of the cylinder. The intrinsic characteristics of the problem suggest us the use of Fourier series to represent both the shape of the cross section and its motion.

Fabrizio Zendri is a Ph.D. student. Here is some excerpt from his current work.

RUMBy (Reduced-scale UnManned BuggY) is an internal project of the Mechatronics Lab aimed at the development of an autonomous vehicle able to drive in dynamic conditions (i.e. high speed). Hardware used in the project is extensively described in this pages; this post discusses the control system architecture (software). In RUMBy a Model Predictive Control (MPC) approach for controlling an autonomous vehicle is used.

The simplified schmatic architecture in Figure 1 describes the main elements of the autonomous vehicle guidance system and it is composed of three main modules: the trajectory/mode planning, the low-level control system , and the vehicle and environmental model.

The research and development center of Dormer Tools based in Rovereto (TN) is searching for two stageaire for research projects on chatter and tool design. Each stage is granted with 2500 EUR.

The call is available here (in italian).

The Doctoral Summer School of the AITeM association will be held in the Faculty of Engineering during the first week of September (1—5 Sept. 2008). A website dedicated to the event is available here.

Here is a gust post by Roberto Fedrizzi and Lorenzo Battisti, two researchers of the University of Trento involved in Wind Energy.

See also the link to the experimental wind energy field

Design and Assessment of “Micro” and “Mini” Class Wind Turbines The turbomachinery Lab is being working with Tozzi Nord to a research project which purpose is the design, analysis and production on a large scale of “micro” and “mini” class wind turbines. Within this project the Turbomachinery Lab is involved into:

- the scientific advice of the research;

- the theoretical and experimental research applied to the choice of suitable aerodynamic profiles for vertical and horizontal axis wind turbines;

- the design of data acquisition systems for testing wind turbines both on the field and into wind tunnels. The Turbomachinery Lab also carries out the above mentioned tests.

The movie presents the tests carried out by the Turbomachinery Lab at the wind tunnel of the Politecnico di Milano. The University of Trento together with Tozzi Nord designed and produced a test bench for the investigation of the fluid dynamic and structural behavior of vertical axis wind turbine rotors. The rotor showed represents the first prototype of “Micro” class wind turbine rotor manufactured by Tozzi Nord during the spring 2007. The test bench allows measuring the torque at the main shaft trough a torquemeter introduced onto the powertrain; an incremental encoder assesses the angular position and rotational speed. The vibrations induced on the structures due to rotation and air flow turbulence are measured by means of 2D accelerometers. Finally, the flexural forces produced on the rotor shaft are evaluated through strain gages setup on the frame.

There is a nice paper about LISA on NATURE|Vol 452|6 March 2008.

“The cosmos is thought to be awash with gravitational waves to which humanity is, as yet, deaf”, says the author, Trudy E. Bell, who reports in a readable article about the future Laser Interferometer Space Antenna experiment. In an effective explanation Trudy shows the readers why LISA is going to be a CORNERSTONE of human view and understanding of the Universe: ”… gravitational waves will throw open whole doors onto an entirely new and vast vista of the Universe”

Trudy interviews some of the most important people of LISA, among which Stefano Vitale (a colleague at the Dept. of Physics, here in Trento), … and there are also words for the engineers (in Trento our colleague Daniele Bortoluzzi and Matteo Benedetti): “A caging mechanism that would release the cubes with zero velocity was one of the toughest engineering problems…”

So, don’t miss NATURE|Vol 452|6 March 2008.

SAFERIDER is a FP7 project for safety of motorcycles. The University of Trento participates with the role of developing ADAS (Advanced Driver Assistance Systems). Here is the official Fact Sheet .