Kinematic Analysis of the Planar Motion of Vehicles when Traveling Along Tractrix Curves

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Giorgio Figliolini ◽  
Chiara Lanni ◽  
Jorge Angeles
Keyword(s):  
Kinematic Analysis ◽  
Front Wheel ◽  
Planar Motion ◽  
Planar Mechanisms ◽  
Straight Line ◽  
Vehicle Motion ◽  
Low Speeds ◽  
Vehicle Chassis

Abstract The kinematic analysis of the planar motion of vehicles, such as common cars, buses, and trucks, when traveling along linear and circular tractrices at low speeds, is proposed here based on the fundamentals of the kinematics of planar mechanisms. In particular, the analysis of the vehicle chassis motion, with chassis represented as a drawbar connecting the back and front-wheel centers, is developed and formulated by determining the moving and the fixed centrodes. The proposed formulation was implemented in matlab to simulate and analyze the vehicle motion at low speeds, as the front-wheel center follows a straight line or a circle and, correspondingly, the back-wheel center traces a linear tractrix or one of the inner and outer circular tractrices, according to the exit from or entrance of the vehicle into a roundabout. Significant numerical and graphical results allow the validation of the proposed formulation, which represents useful tool to predict the vehicle behavior at low speeds during parking, changing of lanes, and entering and leaving roundabouts, thereby increasing the safety for bicycles, motorcycles, and pedestrians, along with the design of safe roads and highways.

Kinematic Analysis of Planar Mechanisms

2020 ◽  
pp. 21-44
Author(s):  
Iulian Popescu ◽  
Liliana Luca ◽  
Mirela Cherciu ◽  
Dan B. Marghitu
Keyword(s):  
Kinematic Analysis ◽  
Planar Mechanisms

An Automated Inversion Apporach to Closed-Form Kinematic Analysis of Planar Mechanisms

1992 ◽  
Author(s):  
Arunava Biswas ◽  
Gary L. Kinzel
Keyword(s):  
Closed Form ◽  
Iterative Methods ◽  
Kinematic Analysis ◽  
Equation Approach ◽  
Planar Mechanisms ◽  
Loop Equation ◽  
Closed Form Solutions

Abstract In this paper an inversion approach is developed for the analysis of planar mechanisms using closed-form equations. The vector loop equation approach is used, and the occurrence matrices of the variables in the position equations are obtained. After the loop equations are formed, dependency checking of the unknowns is performed to determine if it is possible to solve for any two equations in two unknowns. For the cases where the closed-form solutions cannot be implemented directly, possible inversions of the mechanism are studied. If the vector loop equations for an inversion can be solved in closed-form, they are identified and solved, and the solutions are transformed back to the original linkage. The method developed in this paper eliminates the uncertainties involved, and the large number of computations required in solving the equations by iterative methods.

Steering and Stability of Single-track Vehicles

1951 ◽  
Vol 5 (1) ◽  
pp. 191-213 ◽  
Author(s):  
R. A. Wilson-Jones
Keyword(s):  
Lateral Force ◽  
Front Wheel ◽  
Slip Angle ◽  
Single Track ◽  
Motor Cycle ◽  
Low Mass ◽  
Low Speeds ◽  
The Stability ◽  
Straight Ahead

The author briefly states the elementary principles of equilibrium and claims that the stability of the conventional bicycle or motor cycle is automatic except at very low speeds. This is because the steering automatically turns in the direction in which the machine is leaning and returns to the straight ahead position when the machine is restored to the vertical. The achievement of these effects is largely due to the “trail” of the front wheel. The causes of “steering roll” and “steering wobble” and the purpose of the inclination of the steering head, are examined, as are the effects of high and low mass centres and of the rider leaning with and against the machine. It is shown how the elementary principles of steering apply to various types of vehicle, including single-track vehicles in which the necessary lateral force comes mainly from camber thrust rather than slip angle. The results are given of experiments on varying amounts of “trail”, and a method of measuring slip angles is described which is applicable to motor cycles. Finally, a method of indicating the direction of the torque applied to the handlebars when entering, holding, and leaving a bend is described.

A Generalized Approach for the Kinematic Analysis of Planar Mechanisms

1995 ◽  
Vol 209 (4) ◽  
pp. 237-244
Author(s):  
D J A Simpson ◽  
J E L Simmons ◽  
G Moldovean
Keyword(s):  
Computer Program ◽  
Analytical Method ◽  
Building Block ◽  
Kinematic Analysis ◽  
Displacement Velocity ◽  
Planar Mechanisms ◽  
New Approach ◽  
Wide Range ◽  
Complex Mechanisms

This paper describes a new approach to the kinematic analysis of planar mechanisms. The basis of the analytical method is a generic four-bar sub-mechanism which is used as the single building block from which other composite mechanisms may be created. A computer program has been written embodying this method and has been demonstrated to operate successfully providing animated displays of displacement, velocity and acceleration diagrams for a wide range of complex mechanisms.

On the Synthesis of Straight Line, Constant Velocity Scanning Mechanisms

1991 ◽  
Vol 113 (4) ◽  
pp. 464-472 ◽  
Author(s):  
P. H. Hodges ◽  
A. P. Pisano
Keyword(s):  
Constant Velocity ◽  
Transverse Velocity ◽  
Grid Search ◽  
Planar Mechanisms ◽  
Kinematic Synthesis ◽  
Velocity Error ◽  
Straight Line ◽  
Transmission Angle ◽  
Point Motion ◽  
Input Motion

This paper presents a kinematic synthesis of constant-velocity, straight-line coupler-point motion of two planar mechanisms. After the derivation of synthesis equations, the numerical results of a grid search to determine the linkage dimensions for maximum constant velocity, with minimal straight line error, are presented. Plots of acceleration magnitude, transmission angles, and transverse velocity are presented as a function of the percentage of the constant velocity portion of a cycle of input motion. For a 5R2P Stephenson 6-bar linkage, normalized velocity errors as small as 2 percent can be maintained over 40 percent, or more, of the input cycle. A 7R Watt 6-bar linkage, while not achieving quite as high values as the 5R2P linkage, nevertheless can maintain normalized velocity errors as low as 2.5 percent over as much as 39 percent of the input cycle. These levels of performance must be weighed against unfavorable transmission angles, and in many cases, other undesirable effects, such as large accelerations and large transverse travel. The results show that, in order to maintain minimally acceptable transmission angle requirements, the velocity error and scan fraction requirements may be as little as 2.0 percent and as much as 35 percent, respectively.

A New Matrix Method for the Kinematic Analysis and Motion Simulation of Planar Mechanisms With Lower Pairs

1984 ◽  
Vol 106 (4) ◽  
pp. 429-436 ◽  
Author(s):  
P. D. Sparis ◽  
S. G. Mouroutsos
Keyword(s):  
Kinematic Analysis ◽  
Matrix Method ◽  
Degrees Of Freedom ◽  
Motion Simulation ◽  
Planar Mechanisms ◽  
Third Order ◽  
Simulation Procedure ◽  
Improved Accuracy ◽  
Minimal Member

This paper presents a new matrix method for the kinematic analysis and the determination of the velocities, accelerations and jerks for planar mechanisms incorporating rolling, sliding, and pivoting members with a single or multiple degrees of freedom. It also presents a motion simulation procedure that uses the results of the kinematic analysis to estimate the successive positions of the members during the cycle of operation of the mechanism, with third order accuracy in time. Due to the improved accuracy, the proposed motion simulation procedure presents minimal member distortion caused by the accumulation of numerical errors, and does not require iterations for its convergence.

Robust Integrated Design for Vehicle Chassis Based on Uncertainties

2014 ◽  
Vol 644-650 ◽  
pp. 29-32
Author(s):  
Lei Zhang ◽  
Jie Xuan Lou ◽  
En Guo Dong
Keyword(s):  
Integrated Design ◽  
Steering System ◽  
Front Wheel ◽  
Vehicle Performance ◽  
Turning Angle ◽  
Braking System ◽  
Steering Mechanism ◽  
Steering Torque ◽  
Vehicle Chassis ◽  
Noise Factors

In order to improve overall vehicle performance and decrease movement deviation caused by uncertainties from automobile chassis, a robust vehicle chassis model is built with steering system, suspension system and braking system. In the model, the length of the steering trapezoid arm, the bottom angle of trapezoid mechanism, inclination angle, caster, camber and toe-in are defined as controllable variables, and load, driving force, steering torque are defined as noise factors. The optimum objectives include the maximum turning angle error of steering mechanism, the maximum braking sideslip and the maximum swing angle of front wheel on bumpy road. Taguchi method is applied to solve the robust result for automobile chassis model. Compared that the variances of objective values are decreased with the same noise factors and the robustness of sub-systems of chassis is improved.

scholarly journals PRT simulation research

2013 ◽  
Vol 27-28 (3-4) ◽  
pp. 95-102 ◽  
Author(s):  
Maciej Kozłowski ◽  
Włodzimierz Choromański
Keyword(s):  
Simulation Model ◽  
Commercial Vehicle ◽  
Correct Description ◽  
Simulation Research ◽  
Physical Motion ◽  
Straight Line ◽  
Railway System ◽  
Turning Mechanism ◽  
Vehicle Motion ◽  
Curved Track

The paper presents analyses results of PRT vehicle driveability in a ¼ scale conducted with the application of a simulation model for a straight line driving conditions and when driving on a curve. The results of the present work will be used in the analysis of a physical motion model in a laboratory stand reflecting a railway system of the stand. The paper discusses the first stage of research in the process of virtual pre-prototyping which is to be finalized with the construction of a non-commercial vehicle prototype. In the construction of the simulation model, particular attention has been paid to three issues. First of all, a correct description of design features connected with the lack of so called centring mechanism – and not profiled tyred wheels independently embedded in the axes of the set. Secondly, a proper description of a turning mechanism with the use of a leading rollers system alongside the rail edge. Thirdly, the use of linear motor for the vehicle drive. The simulation model has been developed within MBS environment. For the description of tyred wheels, the library of TNO Delft Tyre has been used. Vehicle motion stability has been tested on the straight and curved track sections. The research has been financed within the framework of ECO mobility project.

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