scholarly journals Vehicle Suspension Design Based on a Six-Bar Linkage

Author(s):  
Mark M. Plecnik ◽  
J. Michael McCarthy

A synthesis technique for designing novel vehicle suspension linkages based on the Watt I six-bar is presented. The goal is to maintain near vertical alignment of the wheels to the road during cornering. The complete suspension is analyzed as a symmetric planar 12-bar linkage with ground pivots located at the contact patches. The design procedure specifies the vehicle chassis orientation and the tire camber angles of the vehicle when cornering. As well, two task positions of the wheels with respect to the chassis are specified for suspension movement in straightaways. The result is 18 design equations with 18 unknowns that have a total degree of 2,097,152, though only 336 roots. An example design is presented.

Author(s):  
Yasser Hassan

Design of vertical alignment is one of the main tasks in highway geometric design. This task requires, among other things, that the designer ensure drivers always have a clear view of the road so they can stop before hitting an unexpected object in the road. Therefore, the ability to determine the required and available stopping sight distance (SSD) at any point of the vertical alignment is essential for the design process. Current design guides in the United States and Canada provide simple analytical models for determining the minimum length of a vertical curve that would satisfy the sight distance requirement. However, these models ignore the effect of grade on the required SSD. Alternative approaches and models have also been suggested but cover only special cases of vertical curves. Two specific models were expanded to determine the required SSD on crest and sag vertical curves. By comparing profiles of available SSD and required SSD on examples of vertical curves, it was shown that current North American design practices might yield segments of the vertical curve where the driver’s view is constrained to a distance shorter than the required SSD. An alternative design procedure based on the models was developed and used to determine the minimum lengths of crest and sag vertical curves. Depending on the approach grade, these new values of minimum curve length might be greater than or less than values obtained through conventional design procedures. Design aids were therefore provided in tabular form for designers’ easy and quick use.


2020 ◽  
Vol 53 (7-8) ◽  
pp. 1364-1375
Author(s):  
Feng Cao ◽  
Yongming Li

This work solves the stability problem of a vehicle suspension with stochastic disturbance by designing an adaptive controller. The model of a quarter vehicle subjected to noise excitation is considered. The stochastic perturbance is realized by the roughness of the road and the vehicle moving with constant velocity. In the control design procedure, fuzzy logic systems are used to approximate unknown nonlinear functions. Meanwhile, the mean value theorem is employed to ensure the existence of the affine virtual control variables and control input. The backstepping technique is applied to construct the ideal controller. On the basis of Lyapunov stability theory, the proposed control method proves that the displacement and speed of the vehicle is reduced to a level ascertained by a true “desired” conceptual suspension reference model. Finally, the effectiveness of the proposed method is verified by simulation of electromagnetic actuator servo system.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hui Pang ◽  
Ying Chen ◽  
JiaNan Chen ◽  
Xue Liu

As the road conditions are completely unknown in the design of a suspension controller, an improved linear quadratic and Gaussian distributed (LQG) controller is proposed for active suspension system without considering road input signals. The main purpose is to optimize the vehicle body acceleration, pitching angular acceleration, displacement of suspension system, and tire dynamic deflection comprehensively. Meanwhile, it will extend the applicability of the LQG controller. Firstly, the half-vehicle and road input mathematical models of an active suspension system are established, with the weight coefficients of each evaluating indicator optimized by using genetic algorithm (GA). Then, a simulation model is built in Matlab/Simulink environment. Finally, a comparison of simulation is conducted to illustrate that the proposed LQG controller can obtain the better comprehensive performance of vehicle suspension system and improve riding comfort and handling safety compared to the conventional one.


Author(s):  
Warren S. Hurter ◽  
Nickey Janse Van Rensburg ◽  
Daniel M. Madyira ◽  
Gert Adriaan Oosthuizen

To create an energy efficient vehicle there are a number of aspects that need to be optimized, namely; the drive train of the vehicle and energy source, aerodynamics and weight. Focusing on weight reduction, while still maintaining the desired performance and structural strength, many manufacturers are turning to advanced composites due to their superior strength to weight characteristics. Solar car racing provides a research platform that drives this innovation through technology development and efficiency. A lightweight vehicle suspension system design is being presented, together with an introduction into future testing. A suspension system is made up of a number of critical components which are dynamically loaded during standard operation due to undulating forces imposed by the road surface. Unidirectional cross-wound carbon fiber tubing is used for suspension and steering arms. The tubing is interfaced with small steel inserts and pivoting arm tie rod ends. Concerns within the design are the adhesive bonding of the carbon tubing to the steel inserts, and what type of tensile loading the interface can withstand. Due to forces imposed on the system during cornering and shock loading the components are required to withstand a minimum of 1.2 times the weight of the overall vehicle, i.e. 258 kg. Tensile test results show that the mechanical properties of the adhesive joints rely somewhat on the surface characteristics and bond preparation. The target load of 258 kg was successfully obtained under static loading for two types of sample sets. The first based on the standard for describing the lap shear strength of adhesively bonded carbon fiber to aluminum, and the second based on the working component itself.


2002 ◽  
Vol 8 (7) ◽  
pp. 967-991 ◽  
Author(s):  
Javad Marzbanrad ◽  
Goodarz Ahmadi ◽  
Yousef Hojjat ◽  
Hassan Zohoor

An optimal preview control of a vehicle suspension system traveling on a rough road is studied. A three-dimensional seven degree-of-freedom car-riding model and several descriptions of the road surface roughness heights, including haversine (hole/bump) and stochastic filtered white noise models, are used in the analysis. It is assumed that contact-less sensors affixed to the vehicle front bumper measure the road surface height at some distances in the front of the car. The suspension systems are optimized with respect to ride comfort and road holding preferences including accelerations of the sprung mass, tire deflection, suspension rattle space and control force. The performance and power demand of active, active and delay, active and preview systems are evaluated and are compared with those for the passive system. The results show that the optimal preview control improves all aspects of the vehicle suspension performance while requiring less power. Effects of variation of preview time and variations in the road condition are also examined.


Author(s):  
Prajwal V R ◽  
Chandrashekar Murthy B N ◽  
Yashwanth S D

Active suspension is a type of suspension systems which can vary its damping value in order to adjust the spring firmness in accordance with the road conditions. Real Active Suspension incorporates an external actuator which helps in raising or lowering of vehicle chassis independently at each wheel. Generally, the actuators that are used for active suspension are Hydropneumatic, Electro-hydraulic or Electromagnetic actuators. A new concept of two-way electromagnetic actuation with the help of magnetic damping is proposed in this paper, which can extend its arm on both sides to facilitate active suspension mechanism in both humps and potholes. This increases the ride quality while maneuvering not only in humps, but also in dumps. It also describes about the comparison of spring materials, sophisticated design, construction and working principle of newly proposed actuator. Catia V5 software has been used to design and simulate the actuator model, different spring materials are analyzed and their shear stress and deflections are compared.


2005 ◽  
Vol 20 (3) ◽  
pp. 184-191 ◽  
Author(s):  
Abdullah E. Akay ◽  
John Sessions

Abstract A three-dimensional forest road alignment model, TRACER, was developed to assist a forest road designer with rapid evaluation of alternative road paths. The objective is to design a route with the lowest total cost considering construction, maintenance, and transportation costs, while conforming to design specifications, environmental requirements, and driver safety. The model integrates two optimization techniques: a linear programming for earthwork allocation and a heuristic approach for vertical alignment selection. The model enhances user efficiency through automated horizontal and vertical curve fitting routines, cross-section generation, and cost routines for construction, maintenance, and vehicle use. The average sediment delivered to a stream from the road section is estimated using the method of a GIS-based road erosion/delivery model. It is anticipated that the development of a design procedure incorporating modern graphics capability, hardware, software languages, modern optimization techniques, and environmental considerations will improve the design process for forest roads. West. J. Appl. For. 20(3):184–191.


Author(s):  
V.R. Deulgaonkar

Chassis mounted platform is an intermediate component between vehicle chassis and chassis mounted shelter, and is intended to act as a levelled base for shelters. Shelters in combat vehicles provide a closed stipulated environment to computerized tracking systems, sophisticated defense combat equipments to suit the operational and environmental requirements during warhead situations. Platform carries transfers and sustains unevenness in load arising from the road or soil irregularities during off-road vehicle travel. Present work deals with development, evaluation and improvement of one such platform for 8x8 vehicles. In this work, the platform under consideration is designed to accommodate two shelters, each being secured to the platform using standard twist locking arrangements. Securing locations are dependent on the size and weight of the commodity to be placed inside shelter. Major design ruminations of the platform include nature and pattern of load, flange orientations of channel sections, span between webs of consecutive channels, axle load distribution and vehicle geometry constraints as ground clearance and departure angle. Finite element analysis is carried out in to order evaluate stress and deflection in the present platform configuration. Experimental strain measurement at critical locations on the platform is carried at Automotive Research Association of India (ARAI) to evaluate the performance of the platform under specified load-speed conditions. Relation between experimental stress values and strain gauge locations on the platform is assessed for different load magnitudes.


Author(s):  
Di Chen ◽  
Claus Danielson ◽  
Masahiro Iezawa

Abstract This paper examines using electric vehicles with independently actuated wheels and anti-squat/lift/dive suspensions to improve passenger comfort by reducing the lift, pitch, and roll motion of the vehicle chassis. Anti-squat/lift/dive suspensions use an angled suspension bar to transfer a portion of the longitudinal driving force into a vertical reaction force on the chassis. Using this effect, we derive a control-oriented model of the lift, pitch, and roll of the chassis where the steering angle and the four driving forces of the individual wheels are the control inputs and the road-height is a disturbance. The model is simplified under the assumption that the suspension deflections are small during normal, comfortable driving. Finally, we use steady-state analysis and open-loop simulations to provide intuition about the relationship between the driving forces and the chassis motions.


Sign in / Sign up

Export Citation Format

Share Document