A novel kinematic structure of a tendon-driven mechanism is proposed for an anthropomorphic finge... more A novel kinematic structure of a tendon-driven mechanism is proposed for an anthropomorphic finger mechanism of artificial hands. The kinematic structure is composed by three links as the three phalanges of a human finger and they are moved independently by means of suitable endless tendons. The three d.o.f.s of the proposed open-loop kinematic chain have been appropriately reduced to only one in order to simplify the actuation and control of the finger mechanism. A motion analysis has been carried out by using the polode method to obtain a suitable algorithm for computer simulation. The grasp performances of the proposed new anthropomorphic finger mechanism have been investigated and some design considerations have been pointed out.
This paper deals with the formulation of an algebraic algorithm for the kinematic analysis of sli... more This paper deals with the formulation of an algebraic algorithm for the kinematic analysis of slider-crank/rocker mechanisms, which is based on the use of geometric loci, as the fixed and moving centrodes, the cubic of stationary curvature and the inflection circle. In particular, both centrodes are formulated in implicit and explicit algebraic forms by using the complex algebra. Moreover, the algebraic curves representing the moving centrodes are also recognized and proven to be Jerˇa´bek’s curves for the first time. Then, the cubic of stationary curvature along with the inflection circle are expressed in algebraic form by using the geometric invariants. Finally, the proposed algorithm has been implemented in a Matlab code and interesting numerical and graphical results are shown along with some particular cases in which the geometric loci degenerate in lines and circles.
A detailed analysis of the path traversed by the rear wheels of the bus is useful in highway desi... more A detailed analysis of the path traversed by the rear wheels of the bus is useful in highway design, and in the placement of curbs at intersections. In fact, when a bus turns a corner, the rear wheel could move into the path of a passing motorist or pedestrian by generating an hazard situation, as in the cases of traffic circles and changing lanes. Of course, the same problems regard long trucks, semi-trailer trucks and articulated vehicles, but also bicycles (tandem) and motorbikes. In particular, the path of the rear wheels of a bus or a long vehicle in general, is a tractrix or equi-tangential curve, which is different by that traced by the front wheels. The planar motion of the chassis of the vehicle can be represented by means of the centrodes, which are traced by the instant center of rotation on the ground (fixed centrode) and on the moving plane that is attached to the vehicle (moving centrode), respectively. Thus, the pure-rolling motion of the moving centrode that is represented by the axis of the rear wheel, on the fixed centrode (catenary) can reproduce the planar motion of the chassis. This paper deals with the formulation of a suitable algorithm for the kinematic analysis of the planar motion of vehicles that travel corners, traffic circles and changing lanes. The tractrix is considered as the involute of the fixed centrode (catenary), which takes also the rule of evolute. The inflection and the cuspidal or return circles, along with the Euler-Savary equation and the Aronhold Theorems, give other useful information on the planar motion of the chassis.
The subject of this paper is the kinematic synthesis of volumetric rotary machines, also known as... more The subject of this paper is the kinematic synthesis of volumetric rotary machines, also known as GeRotors (GEnerated ROTORs), which are based on the planetary motion of suitable regular curve-polygons. In particular, the outer and inner conjugate profiles of a generating regular curve-polygon with any number of lobes and different circumcircle and rounded corner radii were synthesized as envelope curves of the polycentric profiles. This also enabled a regular curve-polygon with cusp corners to be obtained, as in the case of the Reuleaux triangle. The proposed formulation was then implemented in a matlab code and validated by means of several significant examples of rotary machines.
The influence of a rough road surface on vehicle vertical vibrations and on the driver and passen... more The influence of a rough road surface on vehicle vertical vibrations and on the driver and passengers is an important research among automotive manufacturers. ISO international standard defines the terminology of vehicle dynamics and roadholding ability. In addition, ISO international standard proposes the test procedures for steady-state circular driving behavior and lateral transient response characteristics against step steering input, sinusoidal steering input, random steering input, and braking in a turn. The standardized test procedure of a double-lane-change test as a severe lane-change maneuver is proposed. In order to estimate the influence of vertical vibration on seated human body, the apparent mass of the human body is evaluated by mechanical lumped models. In this research, a mechanical equivalent model has been developed to characterize the response of the vehicle excited by road profiles. The mechanical equivalent model offers a quantitative evaluation of accelerations of vehicle along vertical axis in terms of natural frequencies and dissipative properties of vehicle. In order to calibrate the mathematical model, an experimental design has been developed by the ride test.
The inspection of structures and infrastructure is nowadays a relevant problem in Europe, and esp... more The inspection of structures and infrastructure is nowadays a relevant problem in Europe, and especially in Italy, after the recent collapses of bridges. Large research activity has been therefore devoted towards the inspection for further management and maintenance of large areas. For those infrastructures difficult to access UAVs, mobile, and climbing robots are the key solution for carrying instrumentation and sensors. UAVs in most of cases are an efficient solution, but they suffer of some drawbacks, among all the security distance to maintain during the flight operation, avoiding the robot to get next to, or in contact to the surface to inspect. Additionally, when dealing with structures exposed to harsh environmental conditions such as strong wind, the possibility of having collisions between to the robot and the surface is quite high. Therefore, to limit possible crashes to surfaces or walls for indoor and even outdoor inspection, wall-climbing drones have been recently conce...
A novel kinematic structure of a tendon-driven mechanism is proposed for an anthropomorphic finge... more A novel kinematic structure of a tendon-driven mechanism is proposed for an anthropomorphic finger mechanism of artificial hands. The kinematic structure is composed by three links as the three phalanges of a human finger and they are moved independently by means of suitable endless tendons. The three d.o.f.s of the proposed open-loop kinematic chain have been appropriately reduced to only one in order to simplify the actuation and control of the finger mechanism. A motion analysis has been carried out by using the polode method to obtain a suitable algorithm for computer simulation. The grasp performances of the proposed new anthropomorphic finger mechanism have been investigated and some design considerations have been pointed out.
This paper deals with the formulation of an algebraic algorithm for the kinematic analysis of sli... more This paper deals with the formulation of an algebraic algorithm for the kinematic analysis of slider-crank/rocker mechanisms, which is based on the use of geometric loci, as the fixed and moving centrodes, the cubic of stationary curvature and the inflection circle. In particular, both centrodes are formulated in implicit and explicit algebraic forms by using the complex algebra. Moreover, the algebraic curves representing the moving centrodes are also recognized and proven to be Jerˇa´bek’s curves for the first time. Then, the cubic of stationary curvature along with the inflection circle are expressed in algebraic form by using the geometric invariants. Finally, the proposed algorithm has been implemented in a Matlab code and interesting numerical and graphical results are shown along with some particular cases in which the geometric loci degenerate in lines and circles.
A detailed analysis of the path traversed by the rear wheels of the bus is useful in highway desi... more A detailed analysis of the path traversed by the rear wheels of the bus is useful in highway design, and in the placement of curbs at intersections. In fact, when a bus turns a corner, the rear wheel could move into the path of a passing motorist or pedestrian by generating an hazard situation, as in the cases of traffic circles and changing lanes. Of course, the same problems regard long trucks, semi-trailer trucks and articulated vehicles, but also bicycles (tandem) and motorbikes. In particular, the path of the rear wheels of a bus or a long vehicle in general, is a tractrix or equi-tangential curve, which is different by that traced by the front wheels. The planar motion of the chassis of the vehicle can be represented by means of the centrodes, which are traced by the instant center of rotation on the ground (fixed centrode) and on the moving plane that is attached to the vehicle (moving centrode), respectively. Thus, the pure-rolling motion of the moving centrode that is represented by the axis of the rear wheel, on the fixed centrode (catenary) can reproduce the planar motion of the chassis. This paper deals with the formulation of a suitable algorithm for the kinematic analysis of the planar motion of vehicles that travel corners, traffic circles and changing lanes. The tractrix is considered as the involute of the fixed centrode (catenary), which takes also the rule of evolute. The inflection and the cuspidal or return circles, along with the Euler-Savary equation and the Aronhold Theorems, give other useful information on the planar motion of the chassis.
The subject of this paper is the kinematic synthesis of volumetric rotary machines, also known as... more The subject of this paper is the kinematic synthesis of volumetric rotary machines, also known as GeRotors (GEnerated ROTORs), which are based on the planetary motion of suitable regular curve-polygons. In particular, the outer and inner conjugate profiles of a generating regular curve-polygon with any number of lobes and different circumcircle and rounded corner radii were synthesized as envelope curves of the polycentric profiles. This also enabled a regular curve-polygon with cusp corners to be obtained, as in the case of the Reuleaux triangle. The proposed formulation was then implemented in a matlab code and validated by means of several significant examples of rotary machines.
The influence of a rough road surface on vehicle vertical vibrations and on the driver and passen... more The influence of a rough road surface on vehicle vertical vibrations and on the driver and passengers is an important research among automotive manufacturers. ISO international standard defines the terminology of vehicle dynamics and roadholding ability. In addition, ISO international standard proposes the test procedures for steady-state circular driving behavior and lateral transient response characteristics against step steering input, sinusoidal steering input, random steering input, and braking in a turn. The standardized test procedure of a double-lane-change test as a severe lane-change maneuver is proposed. In order to estimate the influence of vertical vibration on seated human body, the apparent mass of the human body is evaluated by mechanical lumped models. In this research, a mechanical equivalent model has been developed to characterize the response of the vehicle excited by road profiles. The mechanical equivalent model offers a quantitative evaluation of accelerations of vehicle along vertical axis in terms of natural frequencies and dissipative properties of vehicle. In order to calibrate the mathematical model, an experimental design has been developed by the ride test.
The inspection of structures and infrastructure is nowadays a relevant problem in Europe, and esp... more The inspection of structures and infrastructure is nowadays a relevant problem in Europe, and especially in Italy, after the recent collapses of bridges. Large research activity has been therefore devoted towards the inspection for further management and maintenance of large areas. For those infrastructures difficult to access UAVs, mobile, and climbing robots are the key solution for carrying instrumentation and sensors. UAVs in most of cases are an efficient solution, but they suffer of some drawbacks, among all the security distance to maintain during the flight operation, avoiding the robot to get next to, or in contact to the surface to inspect. Additionally, when dealing with structures exposed to harsh environmental conditions such as strong wind, the possibility of having collisions between to the robot and the surface is quite high. Therefore, to limit possible crashes to surfaces or walls for indoor and even outdoor inspection, wall-climbing drones have been recently conce...
Uploads
Papers by Giorgio Figliolini