A Methodology for Active Control of Multibody Test-Rig for Virtual Simulation of Vehicles Through Acceleration Inputs

2005 ◽  
Author(s):  
Claudio Braccesi ◽  
Filippo Cianetti ◽  
Luca Landi
Keyword(s):  
Active Control ◽  
Dynamic Simulation ◽  
Multibody Systems ◽  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Virtual Simulation ◽  
Test Rig ◽  
Virtual Test ◽  
Signal Drift ◽  
Pave Road

Dynamic simulation through Multibody Systems is more and more used for the design of new industrial products to avoid long and expensive experimental tests on them. The research presented in this paper deals with the realization of an actively controlled virtual test-rig, functional for comfort and durability tests of entire vehicles. The virtual test rig, is capable to impose any experimental acceleration to the centers of the four vehicle wheels through four imposed displacements to the actuators. The active control is implemented with four independent degrees of freedom, one for every actuator. In the paper the active controller logic and its automatic setup will be fully explained. Moreover it will be also explained how to avoid the aliasing and the so called “random signal drift” problems. Finally the results of some virtual pave road experiments to an existing vehicle will be presented.

scholarly journals A contribution to the dynamic simulation of robot manipulator with the software RobotDyn

2004 ◽  
Vol 26 (4) ◽  
pp. 215-225
Author(s):  
Nguyen Van Khang ◽  
Do Thanh Tung
Keyword(s):  
Computer Program ◽  
Dynamic Simulation ◽  
Multibody Systems ◽  
Degrees Of Freedom ◽  
Robot Manipulator ◽  
Theoretical Background ◽  
Tree Structures ◽  
Lagrange’S Equations ◽  
Lagrange's Equations

Robots manipulators are multibody systems with tree structures. In this paper the theoretical background of the computer program RobotDyn is presented. The program is developed using Lagrange's equations and Denavit-Hartenberg matrix. The dynamic simulation of the Robot SCARA with four degrees of freedom is considered as an example of application of the program RobotDyn.

scholarly journals A New Approach of Soft Joint Based on a Cable-Driven Parallel Mechanism for Robotic Applications

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1468
Author(s):  
Luis Nagua ◽  
Carlos Relaño ◽  
Concepción A. Monje ◽  
Carlos Balaguer
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Experimental Tests ◽  
Humanoid Robots ◽  
Inverse Kinematic ◽  
Element Analysis ◽  
New Approach ◽  
Flexible Polymer ◽  
The Mathematical Model

A soft joint has been designed and modeled to perform as a robotic joint with 2 Degrees of Freedom (DOF) (inclination and orientation). The joint actuation is based on a Cable-Driven Parallel Mechanism (CDPM). To study its performance in more detail, a test platform has been developed using components that can be manufactured in a 3D printer using a flexible polymer. The mathematical model of the kinematics of the soft joint is developed, which includes a blocking mechanism and the morphology workspace. The model is validated using Finite Element Analysis (FEA) (CAD software). Experimental tests are performed to validate the inverse kinematic model and to show the potential use of the prototype in robotic platforms such as manipulators and humanoid robots.

A novel approach for experimental identification of vehicle dynamic parameters

2020 ◽  
Vol 234 (10-11) ◽  
pp. 2634-2648
Author(s):  
Di Yao ◽  
Philipp Ulbricht ◽  
Stefan Tonutti ◽  
Kay Büttner ◽  
Prokop Günther
Keyword(s):  
Parameter Identification ◽  
Dynamic Modeling ◽  
Trajectory Optimization ◽  
Dynamic Parameters ◽  
Vehicle Dynamic ◽  
Test Rig ◽  
Vehicle Simulation ◽  
Virtual Test ◽  
Identification Approach ◽  
Measuring Machine

Pervasive applications of the vehicle simulation technology are a powerful motivation for the development of modern automobile industry. As basic parameters of road vehicle, vehicle dynamic parameters can significantly influence the ride comfort and dynamics of vehicle, and therefore have to be calculated accurately to obtain reliable vehicle simulation results. Aiming to develop a general solution, which is applicable to diverse test rigs with different mechanisms, a novel model-based parameter identification approach using optimized excitation trajectory is proposed in this paper to identify the vehicle dynamic parameters precisely and efficiently. The proposed approach is first verified against a virtual test rig using a universal mechanism. The simulation verification consists of four sections: (a) kinematic analysis, including the analysis of forward/inverse kinematic and singularity architecture; (b) dynamic modeling, in which three kinds of dynamic modeling method are used to derive the dynamic models for parameter identification; (c) trajectory optimization, which aims to search for the optimal trajectory to minimize the sensitivity of parameter identification to measurement noise; and (d) multibody simulation, by which vehicle dynamic parameters are identified based on the virtual test rig in the simulation environment. In addition to the simulation verification, the proposed parameter identification approach is applied to the real test rig (vehicle inertia measuring machine) in laboratory subsequently. Despite the mechanism difference between the virtual test rig and vehicle inertia measuring machine, this approach has shown an excellent portability. The experimental results indicate that the proposed parameter identification approach can effectively identify the vehicle dynamic parameters without a high requirement of movement accuracy.

The Mechanical Behavior of Aluminium Alloy Quenching Process

2011 ◽  
Vol 228-229 ◽  
pp. 822-827
Author(s):  
Jia Yuan Luo ◽  
Rong Fan ◽  
Cheng Xiang Shi
Keyword(s):  
Surface Layer ◽  
Aluminum Alloy ◽  
Dynamic Simulation ◽  
Strain Field ◽  
Method Development ◽  
Experimental Tests ◽  
Analysis Method ◽  
Process Dynamic ◽  
Quenching Process ◽  
History Of

Since the aluminum alloy quenching is a complicated and a prompt heat-pressure coupling processing, traditional experimental tests and empirical judgments cannot explain and predict the physical and the force behavior completely during the quenching process. Dynamic simulation of the quenching process is conducted using the finite analysis method. Development laws of the stress and the strain field of the surface layer and core of the alloy during the quenching process are described based on the verification of the simulation. States and process history of the stress and the strain in each phase during the quench are obtained, which provides ponderable data and theoretical value for a fully understanding of the aluminum alloy quenching.

Numerical and Experimental Approaches to Investigate the Stability of a Motorcycle Vehicle

2006 ◽  
Author(s):  
Federico Cheli ◽  
Marco Bocciolone ◽  
Marco Pezzola ◽  
Elisabetta Leo
Keyword(s):  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Experimental Tests ◽  
Roll Angle ◽  
Longitudinal Motion ◽  
Reference Trajectory ◽  
Steering Angle ◽  
Steady State Condition ◽  
The Stability ◽  
Linearized Model

The study of motorcycle’s stability is an important task for the passenger’s safety. The range of frequencies involved for the handling stability is lower than 10 Hz. A numerical model was developed to access the stability of a motorcycle vehicle in this frequency range. The stability is analysed using a linearized model around the straight steady state condition. In this condition, the vehicle’s vertical and longitudinal motion are decoupled, hence the model has only four degrees of freedom (steering angle, yaw angle, roll angle and lateral translation), while longitudinal motion is imposed. The stability was studied increasing the longitudinal speed. The input of the model can be either a driver input manoeuvre (roll angle) or a transversal component of road input able to excite the vibration modes. The driver is introduced in the model as a steering torque that allows the vehicle to follow a reference trajectory. To validate the model, experimental tests were done. To excite the vehicle modes, the driver input was not taken into account considering both the danger for the driver and the repeatability of the manoeuvre. Two different vehicle configurations were tested: vehicle 1 is a motorcycle [7] and vehicle 2 is a scooter. Through the use of the validated model, a sensitivity analysis was done changing structural (for example normal trail, steering angle, mass) and non structural parameters (for example longitudinal speed).

Trajectory Tracking of Underactuated Multibody Systems

2011 ◽  
Author(s):  
Stefan Reichl ◽  
Wolfgang Steiner
Keyword(s):  
Trajectory Tracking ◽  
Multibody Systems ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Feedforward Control ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Differential Algebraic Equations ◽  
State Variables ◽  
Algebraic Equations

This work presents three different approaches in inverse dynamics for the solution of trajectory tracking problems in underactuated multibody systems. Such systems are characterized by less control inputs than degrees of freedom. The first approach uses an extension of the equations of motion by geometric and control constraints. This results in index-five differential-algebraic equations. A projection method is used to reduce the systems index and the resulting equations are solved numerically. The second method is a flatness-based feedforward control design. Input and state variables can be parameterized by the flat outputs and their time derivatives up to a certain order. The third approach uses an optimal control algorithm which is based on the minimization of a cost functional including system outputs and desired trajectory. It has to be distinguished between direct and indirect methods. These specific methods are applied to an underactuated planar crane and a three-dimensional rotary crane.

scholarly journals Comparison of PVD Coatings Nacro4 and TIALN + DLC Deposited on High Contact Ratio Gearing Interacting With Conventional and Ecological Lubricants

2019 ◽  
Vol 22 (2) ◽  
pp. 48-55
Author(s):  
Adam Fürstenzeller ◽  
František Tóth ◽  
Milan Kadnár ◽  
Juraj Rusnák ◽  
Miroslav Bošanský
Keyword(s):  
Experimental Tests ◽  
Load Level ◽  
Maximum Height ◽  
Pvd Coatings ◽  
Contact Ratio ◽  
Test Rig

Abstract Proposed paper deals with experimental tests performed on the Nieman M01 FZG test rig. Experiments were carried out in accordance with STN 65 6280 standard for FZG scuffing tests, from which load values for each load level were obtained. HCR gears made of 16MnCr5 material were utilized during experimental tests. Gear surface was deposited by PVD coatings of nACRo4 and TiAlN + DLC. Conventional lubricant MADIT PP 90H and biological lubricant OMW Biogear S150 were selected for lubrication environments. Aim of the experimental tests lied in application and comparison of PVD coatings deposited on HCR gears. Values of the maximum height of the assessed profile Rz for tip and reference diameters were measured after each load level. Results of experimental tests were statistically processed and relations between the maximum height of assessed profile Rz and load levels for both utilized coatings in both environments were established on the basis of these results.

scholarly journals State Feedback and Torque Feed Forward Combined Control System for Suppressing Drill-Strings Stick-Slip Vibration

2019 ◽  
Vol 37 (2) ◽  
pp. 291-298
Author(s):  
Meng Fu ◽  
Jianghong Li ◽  
Yafeng Wu ◽  
Shubiao Song ◽  
Aiqi Zhao ◽  
...  
Keyword(s):  
Control System ◽  
Degrees Of Freedom ◽  
State Feedback ◽  
Dynamic Performance ◽  
Experimental Tests ◽  
State Observer ◽  
Lumped Parameter Model ◽  
Stick Slip ◽  
Feed Forward ◽  
Reference Governor

In drilling field, drill-strings stick-slip vibration is a common phenomenon and may lead to a series of drilling accidents. In order to improve drilling efficiency, this paper commits to study a new control system to suppress the undesired stick-slip vibration. In this work, a two degrees of freedom lumped parameter model is established to imitate the drill-strings. A state observer is proposed to estimate the unknown drill-strings states. A reference governor is put forward to optimize drilling parameters. In addition, in order to enhance the anti-interference ability of the closed-loop system, a torque feed forward is introduced into the control system. Based on the state observer and the reference governor, a state feedback and torque feed forward combined controller is designed. The simulation results indicate preliminarily that the designed state feedback and torque feed forward controller, compared with the drilling industry PI controller, has better dynamic performance and stronger ability to eliminate the drill-strings stick-slip vibration. Finally, the control system is applied in the drilling field. The experimental tests demonstrate that the designed controller can effectively suppress the drill-strings stick-slip vibration.

scholarly journals Torsion or not torsion, that is the question

2016 ◽  
Vol 25 (12) ◽  
pp. 1644013 ◽  
Author(s):  
Yuri Bonder
Keyword(s):  
General Relativity ◽  
Degrees Of Freedom ◽  
Empirical Support ◽  
Experimental Tests ◽  
Spin Polarized ◽  
Empirical Tests ◽  
New Interactions

A hypothesis of general relativity (GR) is that spacetime torsion vanishes identically. This assumption has no empirical support; in fact, a nonvanishing torsion is compatible with all the experimental tests of GR. The first part of this essay specifies the framework that is suitable to test the vanishing-torsion hypothesis, and an interesting relation with the gravitational degrees of freedom is suggested. In the second part, some original empirical tests are proposed based on the observation that torsion induces new interactions between different spin-polarized particles.

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