DESIGN OF THREE WHEEL STEERING SYSTEM FOR THREE WHEELED VEHICLES

Lecture Notes in Mechanical Engineering, 2018

The purpose of this study is to understand the effects of steering geometry and to develop the proper steering mechanisms of a four-axle vehicle to improve the cornering behaviors. Firstly, based on kinematics and Newtonian mechanics, a 3-DOF steady-state cornering vehicle model, with considering Magic Formula of tire model and simplified suspension model, has been developed. The steady state cornering characteristics of a four-axle vehicle can be found by solving equations of motion. Secondly, implementing the suggested steering geometry, we can determine the optimized design parameters of the steering linkage by using a global search method. It is found that cornering behaviors of this new steering linkage can have better performance than the real four-axle vehicle we chose. Lastly, the effect of the fourth-axle is introduced and included into the investigation. The discussion on the steering geometry arrangements and its effect are presented. Based on the discussions and the design method developed in this work, the steering linkage of four-axle vehicle can be further developed to fit any case by achieving particular steering geometry.

2020

This thesis aims to highlight the design, modelling and explore the theories and techniques behind procedures of developing a rack and pinion steering system for student formula vehicle. This newly designed mechanism will be used in 2017 SAE SUPRA EVENT. Various systems were studied and a simple but very effective rack and pinion steering system was designed with the consideration of the driver. A steering mechanism is a mechanism that helps a vehicle to give direction, the normal standard steering systems available in the market are if ratio 16:1 which means for complete turn of vehicle the steering wheel must be rotated 4 times, a power steering overcomes the problem of rotation and does the full turn in 2 revolutions of steering wheel. As per the guidelines of the SAE SUPRA event power steering was not allowed, hence a need arise to manufacture a steering system that could take a full turn in half rotation of steering wheel, this was accomplished by using a rack and pinion steeri...

Nowadays, the every vehicle existed mostly still using the two wheel steering system to control the movement of the vehicle whether it is front wheel drive, rear wheel drive or all wheel drive. But due to the awareness of safety, four wheel steering vehicles are being used increasingly due to high performance and stability that they bring to the vehicles. In this report, the performance of four wheels steered vehicle model is considered which is optimally controlled during a lane change maneuver in three type of condition which is low speed maneuver, medium speed maneuver and high speed maneuver. Four-Wheel Steering -Rear Wheels Control. For parking and low-speed maneuvers, the rear Wheel steer in the opposite direction of the front wheels, allowing much sharper turns. At higher speeds, the rest wheels steer in the same direction as the front wheels. The result is more stability and less body lean during fast lane changes and turns because the front wheels don't have to drag non-steering rear wheels onto the path.

The 30th SIAR International Congress of Automotive and Transport Engineering, 2019

The stability performances are very important to appreciate the vehicle ability to be driven in different conditions. Starting for a simple planar model of one axle, the motion equations characterizing the rollover or skidding possibility are obtained. These are interpreted as different concerns for the driver, vehicle design engineer or road design engineer. The influence over the vehicle stability is analyzed for different driving conditions as speed, grip coefficient, lateral slope of the ground, position of the vehicle center of gravity, braking or traction intensity, suspension characteristics. Based on the axles stability characteristics, some conclusion were drawn about the steering behavior of the full vehicle. Also, some recommendations for drivers are presented. The procedure presented here can also be used to establish some working algorithms for potential on-board safety systems able to prevent the stability loss.

In modern era, steerability and handling characteristics of the vehicle have become major aspects. Providing comfort to the driver by reducing steering effort without any compromise in steerability and handling of the vehicle is a major concern for automakers. Evaluating handling and steering characteristics of a vehicle in a virtual environment with the help of multi-body system packages saves product development time and cost. The main intention is to improve the steerability and handling of the vehicle by avoiding the steering pull and wheel wandering problems. As per the specification of the selected vehicle Honda CR-V, a multi-body model of the SUV was built in ADAMS/CAR software. The SUV model was validated by comparing simulation results with the standard graphs from literature. Using this model, manoeuvres for different values of wheel geometry parameters, were simulated. The steering effort, steering wheel returnability and the lateral forces produced by the tires were obtained in order to predict the behaviour of the vehicle for different wheel geometry parameters. It can be seen from the results that positive caster angles improve the steering wheel returnability but increase the steering effort. Negative caster angles reduce the steering effort but create wheel wandering problems. Higher Steering Axle Inclination (SAI) angles help in improving the steering wheel returnability and decreasing the steering effort as well. Negative camber angles help in producing higher lateral forces to improve the cornerability of the vehicle. Toe-in angles help in improving the straight-line stability where as toe-out angles help in improving the cornering. Negative scrub radius seem to have stabilising effect on vehicle handling.

2014

In standard 2 Wheel Steering System, the rear set of wheels are always directed forward and do not play an active role in controlling the steering. While in 4 Wheel Steering System, the rear wheels do play an active role for steering, which can be guided at high as well as low speeds. Production cars are designed to under steer and rarely do they over steer. If a car could automatically compensate for an under steer/over steer problem, the driver would enjoy nearly neutral steering under varying operating conditions. Also in situations like low speed cornering, vehicle parking and driving in city conditions with heavy traffic in tight spaces, driving would be very difficult due to a sedan's larger wheelbase and track width. Hence there is a requirement of a mechanism which result in less turning radius. We have developed an innovative 4 wheel steering design to implement a mechanism that can serve the purpose of changing in-phase and counter-phase steering of rear wheels dependi...

In this study, stability control of a three-wheeled vehicle with two wheels on the front axle, a three-wheeled vehicle with two wheels on the rear axle, and a standard four-wheeled vehicle are compared. For vehicle dynamics control systems, the direct yaw moment control is considered as a suitable way of controlling the lateral motion of a vehicle during a severe driving maneuver. In accordance to the present available technology, the performance of vehicle dynamics control actuation systems is based on the individual control of each wheel braking force known as the differential braking. Also, in order to design the vehicle dynamics control system the linear optimal control theory is used. Then, to investigate the effectiveness of the proposed linear optimal control system, computer simulations are carried out by using nonlinear twelvedegree-of-freedom models for three-wheeled cars and a fourteen-degree-of-freedom model for a fourwheeled car. Simulation results of lane change and J-turn maneuvers are shown with and without control system. It is shown that for lateral stability, the three wheeled vehicle with single front wheel is more stable than the four wheeled vehicle, which is in turn more stable than the three wheeled vehicle with single rear wheel. Considering turning radius which is a kinematic property shows that the front single three-wheeled car is more under steer than the other cars.

There are various suspension geometry that can be consider commercial vehicle. Macpherson strut suspension is one of those which are widely used. Since the Macpherson type of suspension with A-arm system consists of several connected parts, the dimensions of each member play a vital role in the variation of steering and suspension angles. In this study, importance has been given to the optimization of suspension geometry and obtaining the optimum locations of the mounting points i.e. hard points of the suspension geometry. A Macpherson strut suspension (front suspension) with A-arm was optimised in Lotus Shark software to obtain the most appropriate locations of the hard points. The main function of steering system in the vehicle is to maneuver both the wheels in desired direction and support the suspension links in riding/static condition. Steering system works along with suspension system. During optimization work of front geometry in vehicle, we have to match steering points and suspension points together to meet at the same Instantaneous Centre (ICR). It is necessary to meet ICR to avoid bump steer and roll steer during riding condition of vehicle. Bump steer is defined as unwanted steer when the vehicle goes in bump condition and roll steer is defined as unwanted steer when the vehicle goes in rolling condition. The other important factors pertaining to the wheel geometry like the caster, camber, toe in and out, scrub radius all depend on the steering geometry. Also, the tire wear is dependent on the steering geometry. To avoid all the problems occurring due to improper geometry and meet required performance parameters, we have to optimize front wheel steering geometry using LOTUS SHARK V4 software. Index terms-Ackerman steering geometry, Caster, Camber, CATIA V5R20, Instantaneous Centre (ICR), KPI, LOTUS SHARK V4, Wheel geometry, Scrub radius, Toe in/out Stages involved-1. Define specification of vehicle model whose steering geometry has to be optimized. 2. Make kinematic model and meet ICRs with the help of CATIA. 3. Define all the points in the kinematic model. 4. Optimize the points of the model to meet the performance parameters. 5. Import the obtained satisfactory points in the LOTUS SHARK software. 6. Verify the performance results and obtain the graphs.

International Journal for Research in Applied Science and Engineering Technology IJRASET, 2020

The steering system being an essential part of the vehicle as it allows the driver to turn the vehicle which includes the steering wheel, steering gear box, pitman arm, drag link, tie rods, steering arms. Rear wheel steering is a well-known technology on which research is still going on but its implementation in real life applications are limited. Convenient front wheel steering does not provide tight turning which make rear wheel steering effective in the agricultural sector, Industrial vehicles are that it offers easy low speed maneuverability and assists in achieving tight turning radius.

SMART MOVES JOURNAL IJOSCIENCE, 2018

The design and manufacture of a 360-degree DC motor and a steering wheel vehicle are designed to reduce the rotation time from one direction to the other. This vehicle can be moved in all directions in the same position by the steering, the pinion, the DC motor, the bearings and the chain drive. The main function of this vehicle is to move easily from one direction to another. The modern development and economic progress of the Indian society have led to an increase of people on the platform, the increase of the vehicle on the road, due to the lack of space, in the hospital is a big problem in the country. The purpose of this study is the development of a system to reduce the radius of the vehicle. In this system, the first vehicle stops and the wheels are turned in the required direction through the driving system and the DC motor. It has a turning radius equal to almost the length of the vehicle itself. This vehicle was used to transport goods in various areas, such as the platfor...

International Journal of Engineering Applied Sciences and Technology, 2020

The Study named "Design and Development of Steering System of an All Terrain " is to search out the acceptable and economical steering mechanism for an all terrain vehicle. For this choice numerous parameters area unit thought about. The geometry for steering is choosed to be Anti-Ackerman geometry. It's choosed to convert the rotational motion into travel motion from Rack and Pinion. The steering column used is of fabric AL6082-T6. The steering wheel is self-designed for the optimization of its size and to scale back its weight. Throughtout the look of wheel technology don't seem to be compromised. The motion of steering wheel is transferred to the tires with the assistance of a combine of tie rods. The tie rods and wheel hubs are connected with self-designed steering arms.

International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2022

This paper describes our first research experience in designing and simulation of a mechanical model or a mechanical system to steer vehicles. As the vehicles is getting more and more autonomous. In this project we created a system or an assembly, The Linear Steering mechanism is designed to steer cars without steering wheels, The project is inspired by Merceries AVTAR vehicle model and aims to develop similar mechanism with concept's learned by us so far. The project can be divided in 3 major parts, First studying basic steering mechanism, second designing, drawing and making CAD model, And lastly Analysis of Model. The designing was done in AutoCAD and Fussion360. We even performed Multibody Dynamics (MBD) in Inspire to determine and analyse forces on system and further performed Finite Element Analysis to determine Factor of safety.

This Study named " Design Methodology of Steering System for All-Terrain Vehicles " is to ensure the most efficient steering assembly selection for an All-Terrain Vehicle. In this process various parameters are kept in mind for an effective selection of Steering system. The Steering system uses a Rack and pinion gearbox for Steering along with this Ackerman geometry is being used for the steering assembly. In this assembly modified Column of Tata Nano car is used which is connected to Rack and Pinion Gearbox by a Universal Joint. The Steering wheel is so designed to meet the weight reduction requirement along with keeping in mind the driver comfort. The Rack and pinion gearbox is connected with Steering arm by the Tie Rods. Tie Rods and Steering arm are being designed and analyzed for their load bearing Capacities.

SAE Technical Paper, 2011

In this paper a four independent wheel-steering system and its application on the HOST prototype are presented. The prototype is a heavy duty vehicle with four wheel motors controlled by wire, so that each wheel is mechanically not-linked to the other ones and has four degrees-of-freedom. Each wheel has an electric steering actuator to move the wheels around the steering axis, which is controlled by wire. The first part of the work deals with the model determination, reducing the four degree-of-freedom system into a one degreeof-freedom system. In the second part, the relationship between the rotations of each wheel and the linear movement of the electric steering is presented. In the third part the steering ratio is calculated and a parameter to reduce the slip angle is defined. In this way a four independent wheel steering model has been developed and applied to the specific characteristics of HOST. Finally the vehicle handling has been tested through simulations of steering-pad and moose-test, in order to verify the stationary and dynamic handling behavior. Despite the model is simplified, owing to the use of the corrective parameter, good performances in terms of turning radius, slip-angle and roll-angle are achieved, increasing maneuverability and stability.

Cross Steering involves the use of a simple kinematic bar mechanism connecting the front and rear hub making the rear wheel to turn in an opposite direction as the front wheels are turned thereby performing the task of reducing the turning radius of the vehicle. This paper aims to design, analyze and simulate the working of cross steering mechanism and to measure its effect on the turning radius of a vehicle. The turning radius of a vehicle is the size of smallest radial turn that a vehicle is capable of making. The use of this mechanism decreases the turning radius considerably which in turn increases the vehicle's maneuverability and its ability to take sharp turns .Therefore the main objective of this paper is to decrease the turning radius as much as possible with minimum stresses and deflection on the cross bar. Through this paper, an optimum design of a cross steering system can be obtained. This setup can be applied on the vehicles which have high ground clearance (Lorry, buses All-terrain vehicles, Sports utility vehicles) and large turning radius. When applied on such vehicles this project has the potential to introduce a new concept for four wheel steering which is simpler and cheaper than any other technique.