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Wheel lift-off and ride comfort of three-wheeled vehicle over bump
Abstract
An in-plane five degree of freedom (dof) mathematical model of a three-wheeled vehicle (TWV) is used to study the influence of bump profiles on occupant injury. The model is validated against vertical acceleration measured when an instrumented TWV is passed over a road bump. Half sine wave, harmonic and cycloidal bump profiles of the same peak height and span are considered. The simulation results indicate that wheel lift-off over bump occurs at the lowest initial longitudinal velocity for cycloidal profile. Estimation using the dominant acceleration peak indicates that even at wheel lift-off speeds, the predicted accelerations are below the tolerance limits. A frequency domain indicates that the level of sustained vibration does not exceed the ISO 2631 and BS 6841 tolerance limits.
... In simulation, to measure the road profile, the first step is to develop the Simulink model for 4 DOF and validate it with 5 DOF and 10 DOF models. Two research papers (Gawade et al., 2004;Paulo et al., 2001) have been taken for validating the results obtained from the model developed in the present work. ...
... Wheel Lift-off and Ride Comfort study of Three-wheeled Vehicle over Bump: 5 DOF (Gawade et al., 2004) A Numerical Model for Passenger Car Ride Comfort Studies: 10 DOF (Paulo et al., 2001) Mass, stiffness and damping properties are taken to be the same as those used for the research papers. The comparison in Figure 5 clearly shows that there is 100% agreement for the vertical acceleration at the half sine wave bump profile. ...
... The fixed length of contact tyre model is considered for ride comfort analysis and the point contact tyre model is considered for road profile measurement. The results of both papers (Gawade et al., 2004;Paulo et al., 2001) match with the new 4 DOF model results. Hence, the new MATLAB/Simulink 4 DOF model is validated. ...
... In simulation, to measure the road profile, the first step is to develop the Simulink model for 4 DOF and validate it with 5 DOF and 10 DOF models. Two research papers (Gawade et al., 2004; Paulo et al., 2001) have been taken for validating the results obtained from the model developed in the present work. ...
... Wheel Lift-off and Ride Comfort study of Three-wheeled Vehicle over Bump: 5 DOF (Gawade et al., 2004) A Numerical Model for Passenger Car Ride Comfort Studies: 10 DOF (Paulo et al., 2001) Mass, stiffness and damping properties are taken to be the same as those used for the research papers. The comparison inFigure 5 clearly shows that there is 100% agreement for the vertical acceleration at the half sine wave bump profile. ...
... The fixed length of contact tyre model is considered for ride comfort analysis and the point contact tyre model is considered for road profile measurement. The results of both papers (Gawade et al., 2004; Paulo et al., 2001) match with the new 4 DOF model results. Hence, the new MATLAB/Simulink 4 DOF model is validated. ...
The aim of international journal of automotive & mechanical engineering (IJAME) is to present the latest development and achievements in scientific research in local and overseas to the world's community especially to simulate and promote academic exchange between the local and foreign scientists, engineers and researchers everywhere. The objective of publishing this journal in English is to strengthen international exchange in academic research. The journal provides the forum for high quality research communications and addresses all aspects of original experimental information based on theory and their applications. The journal welcome contributions from all who wish to report on new developments in automotive and mechanical engineering fields.
... In simulation, to measure the road profile, the first step is to develop the Simulink model for 4 DOF and validate it with 5 DOF and 10 DOF models. Two research papers (Gawade et al., 2004;Paulo et al., 2001) have been taken for validating the results obtained from the model developed in the present work. ...
... Wheel Lift-off and Ride Comfort study of Three-wheeled Vehicle over Bump: 5 DOF (Gawade et al., 2004) A Numerical Model for Passenger Car Ride Comfort Studies: 10 DOF (Paulo et al., 2001) Mass, stiffness and damping properties are taken to be the same as those used for the research papers. The comparison in Figure 5 clearly shows that there is 100% agreement for the vertical acceleration at the half sine wave bump profile. ...
... In simulation, to measure the road profile, the first step is to develop the Simulink model for 4 DOF and validate it with 5 DOF and 10 DOF models. Two research papers (Gawade et al., 2004;Paulo et al., 2001) have been taken for validating the results obtained from the model developed in the present work. ...
... Wheel Lift-off and Ride Comfort study of Three-wheeled Vehicle over Bump: 5 DOF (Gawade et al., 2004) A Numerical Model for Passenger Car Ride Comfort Studies: 10 DOF (Paulo et al., 2001) Mass, stiffness and damping properties are taken to be the same as those used for the research papers. The comparison in Figure 5 clearly shows that there is 100% agreement for the vertical acceleration at the half sine wave bump profile. ...
During a vehicle development program, load data representing severe customer usage is required. The dilemma faced by a design engineer during the design process is that during the initial stage, only predicted loads estimated from historical targets are available, whereas the actual loads are available only at the fag end of the process. At the same time, changes required, if any, are easier and inexpensive during the initial stages of the design process whereas they are extremely costly in the latter stages of the process. The use of road profiles and vehicle models to predict the load acting on the whole vehicle is currently being researched. This work hinges on the ability to accurately measure road profiles. The objective of the work is to develop an algorithm, using MATLAB Simulink software, to convert the input signals into measured road profile. The algorithm is checked by the MATLAB Simulink 4 degrees of freedom half car model. To make the whole Simulink model more realistic, accelerometer and laser sensor properties are introduced. The present work contains the simulation of the mentioned algorithm with a half car model and studies the results in distance, time, and the frequency domain.
... Nominal values for parameters , , , , are directly used from previous studies on three-wheeled vehicle [4,5,33,34], while the parameters , , ℎ are adapted by minimizing a cost function as given in (8), which is the summation of normalized errors of roll angle and roll rate between values obtained from (7) and CarSim. This ensures that the model used for controller design represents vehicle behavior with reasonable accuracy: ...
Three-wheeled vehicles are agile, less complex, but relatively more prone to rollover. The current study focuses on the rollover mitigation control design using active front steering for such vehicles. A lateral load transfer ratio (LLTR) adapted for a three-wheeled platform is presented. Sliding mode control design strategy has been devised which results in pseudo-direct control for roll dynamics of the vehicle. The lag in vehicle roll angle response has been managed using adaptive sliding surface. This concept can be extended for other vehicle configurations. The proposed control scheme is investigated for efficacy using a full vehicle simulation model of CarSim software and National Highway Traffic Safety Administration’s proposed Fishhook maneuver. The controller is able to limit the rollover propensity even with vehicle parameter uncertainties.
... Model parameters were set for typical three wheeled motorised taxis currently plying in subcontinent using data available in [6], [10], [11]. The sequence of calculations is shown in the Figure 2 ...
Three wheeled vehicles (TWV) are a common low cost mode of transport in the Asian Subcontinent, Africa and South America. It is very prone to rollover in turns even at moderate speeds. Recently anti-roll bars (ARB) have been installed claiming increase in rollover thresholds for (one front two rear) 1F2R wheel configuration. Roll moment is resisted at the rear axle only. Rear Axle installed ARB typically increases over-steer tendency. In the current study a Six degrees of freedom model is used to investigate the effect of ARB stiffness on the rollover threshold.
... Model parameters were set for typical three wheeled motorised taxis currently plying in subcontinent using data available in [6], [10], [11]. The sequence of calculations is shown in the Figure 2 ...
Three wheeled motorized vehicles are a very popular mode of public transport in many countries. Theses vehicles are prone to overturning even during normal turning and obstacle avoidance maneuvers. In this paper, the mathematical model of this three wheeled vehicle is analyzed using Simulink and from this analysis some guidelines for improving the overturning stability in terms of vehicle geometry and suspension properties are suggested. The vehicle is simplified as a nonlinear six-degree of freedom independent suspension vibratory model and the differential equations governing the dynamic behavior of the vehicle are derived. These differential governing equations are modeled in Simulink and vehicle response is then simulated for different steering angle, engine power and braking inputs. For given input data from Bajaj, the reaction force on each wheel for different steering angle and engine power are found out and then the threshold velocity for overturn for different driving condition is found out. The effect of vehicle geometry (height of center of gravity, wheel track length, distance of center of gravity from rear and front wheel) and suspension properties (stiffness, damping) on overturning stability are the obtained by simulating the model. Theses results indicate some guidelines for the optimum design of the vehicle geometry and suspension system. It is shownthat one of the main advantages of Simulink is accurate analysis with considerable reduction in time and effort compared with conventional numerical solution procedures adopted so far.
SYNOPSIS Initially the vehicle response during braking is investigated with the aid of a mathematical model having a realistic road input. Using an integrated hybrid computer, the road-tyre characteristics are simulated by generating non-linear functions on the digital computer, while the mathematical model is described on the analogue computer with parallel logic facility. An adaptive braking control system is proposed which measures and processes the rear-wheel motion. Activation of the system occurs when the wheel deceleration and a quasi wheel slip reach given reference values. The adaptive system as developed and optimised on the hybrid computer is implemented on the rear wheels of the test vehicle. The predicted values of wheel speed, brake-pressure modulation, stopping distance and vehicle yaw are shown to compare favourably with the test results.
During a seven-month survey from May to November 1985, 624 victims injured from three- or four-wheeled all-terrain vehicles (ATVs) were observed in the emergency rooms of 10 regional hospitals in Quebec. A total of 1,100 injuries were identified, including 3 fatal and 104 serious to critical injuries (AIS greater than or equal to 3). These injuries were to the lower limb (29%), the upper limb (28%), the head, neck, and face (26%), and the thorax, abdomen, and pelvis (18%). Close to one-half (45%) of the victims were 19 years old and less; 54% reported wearing helmets. Ten percent of the victims were hospitalized for an average period of 8 days. In 70% of the cases, the vehicle overturned: half of these vehicles turned on the side, 27% toward the back, and 19% flipped forward. Two-thirds of persons injured were involved in accidents in which no external objects were hit by the vehicle; these accidents typically involved vehicle overturns, both on hills and on level ground. Ninety-five percent of the vehicles were in good mechanical condition. The use of these vehicles presents a danger whether used by a child or an adult, by an experienced or an inexperienced rider. The average user may not be aware that three- and four-wheel ATVs demand considerable skill and caution. We suggest the use of accident reconstruction studies for possible engineering solutions.