Ionut Geonea

Numerical Simulations and Experimental Human Gait Analysis Using Wearable Sensors

The paper presents a comparison between an experimental study of flexion-extension movement in human legs joints and numerical simulations on a virtual mannequin computed in ADAMS virtual environment. Using Biometrics system which is a data acquisition system based on electrogoniometers, data were collected for the right and left ankle, knee and hip during experimental gait overground on force platforms. The mean flexion-extension cycles for legs joints were obtained. The obtained experimental data series were be introduced as input data in the joints of the virtual mannequin and a walking simulation was performed in ADAMS environment software. The variation of ground forces during walking are obtained by experimental data and by virtual simulation.

Dynamic Analysis of an Exoskeleton New Ankle Joint Mechanism

In this paper, a dynamic analysis is performed for a new ankle joint mechanism used on an exoskeleton structure. The designed exoskeleton structure will be used in human rehabilitation purposes. The aim of this research is to determine the connection forces through an inverse dynamic analysis in order to use these for numerical simulations of the proposed prototype. The obtained results validate the design techniques, which demonstrates the engineering feasibility of the proposed design.

Design and Simulation of a Single DOF Human-Like Leg Mechanism

In this paper is carried out the selection and simulation of a one degrees of freedom (DOF) leg mechanism. The leg mechanism consist of a nine bar linkage and is based on a Low-cost Easy-operation idea. Virtual simulation tests of the model shows the feasible of the proposed leg mechanism, for human leg motion assistance. Kinematics and dynamics analysis of the leg mechanism is carried out. Finally, dynamic simulation results reveal the motion characteristics and performance of the leg mechanism.

Kinematic and Dynamic Study of a Mechanism for a Vehicle Front and Rear Stabilizer Bars

In this paper, a method is described for theoretical and experimental studies of a front and rear stabilizer bars used on vehicle steering and suspension systems. Based on the fatigue experimental tests performed on a special test-bed, a complex actuation mechanism from the test bed structure will be analyzed. This mechanism through his kinematic and dynamic structure assures complete conditions for simulating the dynamic behavior in a complex mode of the rear stabilizer bar used on a vehicle steering and suspension structures.

Design and Motion Analysis of a Powered Wheelchair

This paper presents researches developed by authors to design a motorized robotic wheelchair for disabled people. These devices enable disabled people perform many activities of daily living thus improving their quality of life. Proposed solution uses for traction one DC motor with steps adjustable angular speed, and for steering one smaller motor. It is presented the kinematic scheme of the proposed transmission and kinematic analysis. It is developed a CAD model of the transmission, mounted on a wheelchair. They are made simulation in Adams, in order to verify the functionality of the proposed transmission. The obtained results validate proposed transmission model and enable success implementation of this transmission to a wheelchair experimental model.

New Assistive Device for People with Motor Disabilities

In this paper, a new mechanism for human leg motion assistance for rehabilitation purposes has been proposed. The structure of human leg and its motions have been used as inspiration for design purposes. A 3D model of the proposed system has been elaborated in Solid Works®, both for design and simulation purposes. It is developed a kinematic model of the mechanism, useful for further design optimization. There has been build an experimental model of the mechanism and they are conducted experimental researches. The result shows that the proposed mechanism performs movements similar to those of a human leg.

Design of a Test Rig for Vehicle Stabilizer Bar Fatigue Study

In this paper the design, experimental and numerical simulation of a test rig for stabilizer bars fatigue resistance study is presented. A virtual CAD of the test rig is developed, for design and simulation purposes. A dynamic simulation model is developed in ADAMS software, to study the stabilizer bar durability. Strain gauge transducers are used to measure the deformations of the stabilizer bar.

Experimental and theoretical study of friction torque from radial ball bearings

In this paper it is presented a numerical simulation and an experimental study of total friction torque from radial ball bearings. For this purpose it is conceived a virtual CAD model of the experimental test bench for bearing friction torque measurement. The virtual model it is used for numerical simulation in ADAMS software, that allows dynamic study of multi-body systems and in particularly with facility Adams Machinery of dynamic behavior of machine parts. It is manufactured an experimental prototype of the test bench for radial ball bearings friction torque measurement. In order to measure the friction torque of the tested bearings it is used an equal resistance elastic beam element, with strain gauge transducer to measure bending deformations. The actuation electric motor of the bench has the shaft mounted on two bearings and the motor housing is fixed to the free side of the elastic beam, which is bended by a force proportional with the total friction torque. The beam elastic element with strain gauge transducer is calibrated in order to measure the force occurred. Experimental determination of the friction torque is made for several progressive radial loads. It is established the correlation from the friction torque and bearing radial load. The bench allows testing of several types and dimensions of radial bearings, in order to establish the bearing durability and of total friction torque.

Vehicle Steering Mechanism Elastodynamic Analysis

In this paper is performed an elasto-dynamic study of a steering mechanism from a road vehicle. Kinematical studies of the steering mechanism have been made especially on robots, their results being presented in scientific literature. The main purpose of this study is to reduce tires wear by optimizing the components of the steering mechanism.

Dynamic Modelling and Simulation of an Auto Vehicle Steering Mechanism Considering its Elements as Flexible

The paper presents the dynamic analysis of a steering mechanism for a road vehicle, considering the deformability of some elements, such as the steering tie rods. Both the steering and suspension mechanisms were analysed form structural point of view. The kinematic scheme of the assembly was done, followed by a study of their parts and kinematic joints. Then, there was calculated the degree of mobility of the mechanism. The dynamic analysis was approached in case of a stationary vehicle. Considering the geometry of the real model, it was designed the 3D model of the mechanisms assembly. Respecting the positioning on the vehicle, the model was exported to the Adams View software, where the components were assembled, defining the kinematics joints. The values obtained by simulations are compared to those obtained by experimental means. Also, results can be used to optimize aspects of the mechanical system. Finite element analysis was performed to study the contact stress distribution of the rack and pinion gear, considering wheels-road contact and also the friction from the spherical and cylindrical joints of the mechanism. The rack and pinion gear was defined by coupling the rotational motion of the pinion with the translation of the rack.