Wheel Force Research Articles

Effect of Wheel Force Transducer’s Mass on Measurement Precision and Whole Vehicle Stability

The wheel force transducer(WFT) delivers the forces serially from road to tire and adds 4 kg to 10 kg mass to whole wheel,so how the additional mass affects the measuring precision of WFT and the stability of whole vehicle should be analyzed quantitatively.Two resistance strain gauge WFTs with 8 beams and 4 beams are employed respectively,and the model analysis are conducted for elastic body,original rim,the assembly of elastic body and modified rim.Then the additional deformation of elastic beam,motivated by the rotation centrifugal force of whole wheel and the vertical motion inertia force of elastic body outer ring,are analyzed comparatively.15 DOF whole vehicle model is developed and 160° hand-wheel angle step input simulations with 90 km/h uniform speed are conducted,for quantifying the effect of WFT on vehicle stability based on sideslip angle and yaw rate.The research shows that the main factors increasing the measurement errors of WFT are elastic beam's stretch and bending deflection both in the 1st frequency vibration of elastic body and motivated by the vertical motion inertia force of elastic body outer ring;the additional mass can change the vehicle stability and increase the response delay time.

자석대차를 이용한 화물창 내 자동 도장로봇에 대한 연구

Abstract In order to build a ship, painting on ship cargo tank is one of the most dangerous parts as it involves working in high altitudes and a closed ship cargo tank. Therefore, researchers have been developing devices that will enable mobile robots to operate on vertical walls. The wall-climbing robots have been widely used to attach on the wall such as suction types. These types can be utilized regardless of the wall material. However, it is required to adhere and control the suction cups. To moderate this drawbacks, this paper proposes an automatic painting robot that uses a permanent magnet mobile robot. Using the magnetic characteristics, this robot can move on the boat vertically and horizontally even while hanging on the ceiling of the ship cargo tank. Also, we made a prototype to test adhesive force of the permanent magnet wheel and mobile robot as well as the towing capacity and auto-piloting ability. Key Words : Ship Cargo Tank, Automatic Painting Robot, Permanent Magnet Wheel, Permanent Magnet Mobile Robot

Accuracy Analysis of Grinding Indexable Inserts Related to the Centrifugal Force of High Speed Abrasive Wheel

When grinding the carbide insert with the abrasive wheel at high rotating speed, the accuracy of inserts is impacted by the changed size of abrasive wheel by the centrifugal force. This paper proposes a computing model of grinding location for insert, and giving an analysis of dynamic simulation of the abrasive wheel at high rotating speed. The analysis showed which the diameter of wheel is enlarged, and its axial size is indented. According to the result, some geometrical parameters offsets were afforded to realize to grind inserts accurately in the CNC grinding machine tool.

An alternative approach to automotive ESC based on measured wheel forces

Traditional electronic stability control (ESC) systems act on one or more wheels on the basis of a logic aiming at the control of variables that cannot be directly measured (vehicle sideslip angle and the tyre slip). Hence, a vehicle state estimator capable of evaluating the needed variables from the data of the input sensors is necessary. In the present paper, the authors discuss a different approach to the estimation problem, assuming that the forces acting on the wheels can be directly measured. The ESC feed-forward control logic is designed through a vehicle frequency response analysis in order to obtain a faster active system activation. The variable controlled by the logic is the tyre longitudinal force. Experimental results obtained on an ESC hardware-in-the-loop test bench prove the validity of the approach, showing enhanced dynamic performances, together with the limits due to the delays in the actuation of the ESC motor pump, which needs some time to build the pressure requested for the intervention on the selected callipers. Finally, the tests demonstrate the opportunity of closing the control loop on a variable (i.e. the force) that can be directly measured.

Longitudinal force distribution using quadratically constrained linear programming

In this paper, a new method is presented for the optimisation of force distribution for combined traction/braking and cornering. In order to provide a general, simple and flexible problem formulation, the optimisation is addressed as a quadratically constrained linear programming (QCLP) problem. Apart from fast numerical solutions, different driveline configurations can be included in the QCLP problem in a very straightforward fashion. The optimisation of the distribution of the individual wheel forces using the quasi-steady-state assumption is known to be useful for the study of the influence of particular driveline configurations on the combined lateral and longitudinal grip envelope of a particular vehicle–driveline configuration. The addition of the QCLP problem formulation makes another powerful tool available to the vehicle dynamics analyst to perform such studies.

EBZ160 Star Wheel Boring Machine Loading Mechanism Optimization Analysis

In order to ensure the boring machine to work, star wheel loading mechanism must have good loading properties. The force of star wheel of EBZ160 loading mechanism is analyzed based on the creation of three-dimensional model of star wheel by using PRO/E software. Static analysis is done by importing the three-dimensional model of the star wheel in ansys. Checking the strength of the program star wheel. Based on the meet of the strength of the star wheel, topology optimization is done by using the OC method. The results obtained from topology optimization can be seen, basically meet the requirements of this program the amount of material is decreased by 20kg than before. The theoretical basis of improving star wheel design and improving performance is obtained.

Exploring new fields of virtual load prediction by accurate tire simulation for large deformations and flexible rim support

AbstractDuring the past ten years, there has been a significant trend in automotive design using low aspect ratio tires and increasingly run‐flat tires as well. In recent publications, the influence of those tire types on the dynamic loads – transferred from the road through the wheel into the car – have been examined pretty extensively, including comparative wheel force transducer measurements as well as computational results. It can be shown that the loads to the vehicle tend to increase when using low aspect ratio tires and particularly when using run‐flat tires. These tires provide higher stiffnesses while simultaneously introducing larger nonlinearities in the sidewall behavior [1–3]. Depending on manufacturer and the combination of vehicle size and wheel properties, these deformations can be so large that the tire belt and/or sidewall have contact with the rim crown (protected by the tire sidewall). The full vehicle simulation on virtual proving grounds is well established and important for the vehicle product development process. One of the most important subsystems in the virtual load assessment process, using full vehicle simulation is the tire model. The precision of that is essential for the overall accuracy of the virtual method. So the tendencies described above strongly require adaptations and improvements in the field of tire modeling. In 2007, Fraunhofer LBF together with Honda R&D started to examine the influences of low aspect ratio and run flat tires for the accuracy of full vehicle simulation results for durability relevant scenarios [3–5]. Those activities were the starting point for a four years joint activity to extend the usability of the virtual load prediction method by full vehicle simulation to application for which strong nonlinearities in the tire (large very transient deformation), but also in the vehicle model itself occur. As a part of that joint development, this paper summarizes the activities of Fraunhofer LBF to develop a dedicated tire model, which can accurately handle very large deformations of the tire up to misuse‐like applications. The model is based on the LBF tire model CDTire. In the first chapter several nonlinear extensions of the belt and sidewall model will be described which have been implemented to capture the large deformation behavior. These model extensions are also taking into account the belt‐to‐sidewall and sidewall‐to‐rim contact. To validate and to parameterize these model extensions, Fraunhofer LBF built a dedicated flat track test rig, which can be used to realize “roll‐over‐cleat” experiments using huge obstacles, so that belt‐to‐sidewall and sidewall‐to‐rim contact can be forced. This test rig will be described in chapter 2. The third chapter is dealing with the interface of the new tire model to a flexible rim. While the load transfer from road via tire into the vehicle is relatively easy to detect, for example by using wheel force transducers, the local forces acting on the rim flanges as well as on the wheel well (when e. g. passing a curb) are much more difficult to detect (in measurement as well as in simulation). LBF developed a method to detect local tire‐to‐rim interface forces and manage flexible rim simulation in Multi‐Body‐Simulation (LMS Virtual. Lab Motion – [6]). One key issue of the overall method is the capability of the tire model to predict local rim forces on the rim flanges in a suitable way. The second key issue is to combine the tire with a model of a flexible rim (which is embedded in a full vehicle MBS model). This method can be used to perform virtual load prediction of local, transient rim forces, which are the basis for CAE based fatigue life prediction of wheels applying typical durability test track and abuse load events.

Development of a Cornering Bench Fatigue Test for the Validation of a Lightweight Commercial Vehicle Front Hub

Laboratory testing to validate the performance of vehicle components is a common practice in the automotive market. However, during standard bench testing of a commercial front wheel hub, several failures occurred in unexpected regions indicating an inconsistency with the vehicle cornering tests. This article addresses this inconsistency and presents methods for fatigue assessment using an accelerated rig (bench) test for a lightweight commercial vehicle front wheel hub. A complete cornering (figure of eight) vehicle test is modeled on a multi-body dynamic simulation system (ADAMS/Chassis) and the results are compared with the actual data obtained from the hub of a vehicle instrumented with a set of wheel force transducers. The multi-axial loading condition is successfully simplified due to the dominance of some stress components. Load data from the simulation are processed with the rain flow cycle counting algorithm. Critical locations on the C55 steel hub are determined with the stress analysis done on ANSYS (ANSYS Theory Reference: Release 10.0, 2005). Total damage is estimated by using the Palmgren–Miner linear damage summation rule. Finally, some validation test results are consistent with vehicle tests and may be used to substitute performance.

고속철 PSC 박스거더 교량의 통과차량 윤하중 동적해석

현재 공용중인 고속철 차량(KTX)과 궤도 그리고 교량 구조물을 총괄적으로 고려한 해석모델을 개발하여 고속철 차량의 교량 통과시 임계속도(300~315 Km/h)에 대한 차량 윤하중의 동적 거동특성을 해석하였다. 해석차량은 적용가능한 모든 운동조건을 고려하여 고속철 동력차를 38자유도 모형으로 개발하였고, 차체와 대차의 연직 변위, 횡 변위, 종 변위 및 피칭, 롤링, 요잉을 모두 고려하였다. 대상교량은 PSC BOX 교량으로 각각 25 m, 30 m, 35 m, 40 m 경간길이를 갖는 단순교를 3차원 공간뼈대 요소를 사용하여 모형화 하였고, 궤도의 불규칙성은 정상 확률과정으로 가정하여 지수스펙트럼 밀도함수를 사용하여 설정하였다. 개발된 교량, 궤도, 열차모델을 총괄적으로 해석하여 주행하는 고속철 차량이 각 경간별 교량을 통과하는 과정에서 발생하는 차량 윤하중과 일반도상 통과시 발생하는 윤하중을 Runge-Kutta 기법으로 산출하여 비교 분석하고, 교량 경간길이 별 차량속도에 따른 윤하중 스펙트럼을 분석하고자 한다. A dynamic analysis procedure is developed to provide a comprehensive estimation of the dynamic responses of locomotive's wheels running over a Pre-Stressed Concrete (PSC) box girder bridge on the Korea high speed railway. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyze accurately and evaluate with in-depth parametric studies of the bridge lengths (25, 30, 35, 40 m) for dynamic responses of railway vehicle wheel forces due to the critical crossing speeds (300~315 km/h) on the bridges. The high-speed railway locomotive (KTX) is used as 38-degree of freedom system. Three displacements (vertical, lateral and longitudinal) as well as three rotational components (pitching, rolling and yawing) are considered in the 38-degree of freedom model. Three dimensional frame element is used to model the PSC box girder bridge, simply supported span length of 40m. The irregulation of rail-way is derived using the exponential spectrum density function under assumption of normal probability procedure. The results of dynamic analysis by Runge-Kutta method which are able to analyze considering the dynamic wheel forces between bridges and normal rail-ways are compared and contrasted. It is presented as an wheel forces spectrum that is varying either the bridge lengths or the critical crossing speeds.

A nonlinear sideslip observer design methodology for automotive vehicles based on a rational tire model

In this paper we develop a nonlinear vehicle sideslip observer design that is based on a nonlinear lateral dynamics vehicle model. In doing so we utilize a novel simplified rational tire model to compute the lateral wheel forces. This tire model is significantly simpler than the well known Magic Formula (in terms of the number of model parameters), yet it provides sufficient detail over a wide range of operating conditions for the purpose of estimating the sideslip angle. The input to the nonlinear observer are typical signals that are available within lateral stability control systems, which include vehicle speed, steer angle, lateral acceleration and yaw rate measurements. In our analysis, we assume the road friction to be a known parameter. We utilize a recent theorem from the literature and show that the suggested nonlinear state estimator a) is asymptotically stable for the case where the observer makes use of the exact tire model, b) is stable (in the sense of Lyapunov) providing uniformly bounded error dynamics for the case where it makes use the proposed rational tire model to approximate the exact tire model. Finally, we provide numerical simulations to demonstrate the efficacy of our nonlinear observer based estimation technique under varying road friction conditions.

Improvement of curving performance by expansion of gauge widening and additional measures

Lateral forces between wheels and rails must be reduced in order that rolling stock runs safely and smoothly on curved tracks. The excessive lateral force will cause not only derailment of rolling stock but also destruction of tracks, rail corrugation, track irregularity, squeal noise and wear. It is important to reduce lateral force of wheels in curves, so new wheel-tread profiles and steerable bogie structures have been developed up to now, however, they cannot solve various problems in curving perfectly. In this article, the authors propose three methods for improvement of running performance on curves by using existing types of wheels and rails, and analyse the effects of three methods by numerical simulation. According to analytical results, the authors conclude that ‘expansion of gauge widening’, and ‘larger rail inclination angle of inner rail installation’ or ‘asymmetrically inclined grinding of inner rail head’ can get sufficient rolling radius difference, and are effective for improvement of running performance on curved tracks.

Analysis on Vehicle-Bridge Coupled Vibration of a Rigid-Frame Arch Bridge Based on Measured Road Roughness

Firstly, synchronous field measurements were carried out for the road roughness of the left and right wheels to obtain the roughness profile using a high speed laser roadway testing vehicle. Secondly, programming idea of multi-girder vehicle-bridge coupled vibration analysis module was presented briefly. Finally, a three-axle heavy truck crossing a rigid-frame arch bridge was taken as an example, detailed comparing and analyzing was carried out for the influence on the dynamic responses and spectrum characteristics of the vehicle-bridge system from three excitation cases which include using measured road roughness corresponding respectively to left and right wheels, using measured road roughness of left wheels and right wheels simultaneously. The analysis shows that when the differences in road roughness between left and right wheels are significant, the responses computed with inconsistent excitation is smaller than that with both of the latter two excitation cases, and there are some differences between the vertical contact forces of wheels and the spectrum characteristics of the vehicle-bridge system.

Research on Nonlinear Coupling Analysis Based on Polynomial Model

For a multi-dimension force transducer, the mutual coupling between any two force transducers is unavoidable, and normally, the coupling characteristic is nonlinear. But the nonlinear coupled transducers are often treated as linear coupled ones since the difficulty of nonlinear decoupling. The 6-axis wheel force transducer (WFT), as the key instrument of vehicle roadway test system, the precision of which is influenced badly by the mutual coupling. The linear coupling analysis and decoupling method was introduced, on the basis of which, the polynomial nonlinear coupling model was derived, and the polynomial nonlinear decoupling method was discussed. The measurement data of WFT were processed. The results indicate that the accuracy of nonlinear decoupling is higher than that of linear decoupling.

Effects of Multiblocking and Axial Gap Distance on Performance of Partial Admission Turbines: A Numerical Analysis

In this paper, the effects of axial gap distance between the first stage stator and rotor blades and multiblocking on aerodynamics and performance of partial admission turbines are analyzed numerically. The selected test case is a two stage axial steam turbine with low reaction blades operating with compressed air. The multiblocking effect is studied by blocking the inlet annulus of the turbine in a single arc and in two opposing blocked arcs, each having the same admission degree. The effect of axial gap distance between the first stage stator and rotor blades is studied while varying the axial gap by 20% compared with the design gap distance. Finally, full admission turbine is modeled numerically for comparison. Performance of various computational cases showed that the first stage efficiency of the two stage partial admission turbine with double blockage was better than that of the single blockage turbine; however, the extra mixing losses of the double blockage turbine caused the efficiency to deteriorate in the downstream stage. It was shown that the two stage partial admission turbine with smaller axial gap than the design value had better efficiency of the first stage due to lower main flow and leakage flow interactions; however, the efficiency at the second stage decreased faster compared with the other cases. Numerical computations showed that the parameters, which increased the axial force of the first stage rotor wheel for the partial admission turbine, were longer blocked arc, single blocked arc, and reduced axial gap distance between the first stage stator and rotor blades.

A novel sensor design for the tyre load monitoring: overall design and analysis

The growing demand for safety, comfort, and ride performance in the automotive industry motivates the design of advanced sensory systems. In this work, a sensory system is designed which measures the wheel forces and moments in every direction. The design benefits from a compact configuration by only modifying one part of the vehicle's current wheel assembly. The forces and moments are measured using the deflections of a flexible cylindrical layer embedded in the external hub of the wheel bearing assembly, where all the loads transmit through.

Implementation and evaluation of force allocation control of a down-scaled prototype vehicle with wheel corner modules

The implementation of wheel corner modules on vehicles creates new possibilities of controlling wheel forces through the utilisation of multiple actuators and wheel motors. Thereby new solutions fo ...

Adaptable Mechatronic Locomotion System

Wheeled in-pipe locomotion is very favourite principle of locomotion used inside pipe. However, there are several problems in these systems like slipping or deadlocking on inner pipe wall. The construction of the system provides adaptation of the wheels position i.e. adaptation of the normal force of the wheels against to the inner pipe wall. This property is important, because of geometric deviations on inner pipe wall. Information about the actual normal force of wheels against the inner pipe wall is used for regulation of their value. When normal force is too small then slipping occurs, but if normal force is too large then deadlocking occurs. A designed system is able to adapt to pipe with inner diameter in range of 100mm to 200mm.

Semiempirical model of a wheel-soil system

Developing new concepts for the prediction of off-road traction is becoming essential as an increasing number of sport utility vehicles (SUVs), sport activity vehicles (SAVs), and other off-road vehicles arrive on the market. The prediction of off-road traction is a difficult problem because of the number of factors affecting wheel performance on soft soils or snow. Most of the existing methods for wheel-soil thrust prediction are based on Coulomb’s equation, in which stresses acting on the wheel-soil contact patch are analyzed. The objective of this work was to develop a new method to infer mathematical models of a wheel-soil system in which soil-stress states are correlated with the forces acting on a road wheel. A set of model equations is obtained by means of the system identification method with the use of experimental data gathered in the field with real vehicles. This paper includes a description of the experimental setup, procedures, and methods used in the tests. The experimental method is based on simultaneous measurements of the soil-stress state and wheel forces during test runs of an instrumented vehicle over soft soil surfaces. Soil-stress states consist of three principal stresses and their direction cosines, which are determined with the use of a stress state transducer (SST) placed at a depth of 15–30 cm under the wheels. Longitudinal, vertical, and transverse wheel forces are measured with a six-element wheel force transducer. The wheel forces obtained in the test runs are correlated with the respective soil stresses. Based on the data, three families of models were obtained by means of the system identification method.

Estimation of momentary wheel force coefficients by using a fusion of drive dynamic sensors and GPS data

This paper presents a method to determine the momentary lateral and longitudinal force coefficients by calculating lateral, longitudinal, and vertical forces at the wheels. The longitudinal forces of the wheels are calculated for known accelerationand braking torques. A rigid body model is used to determine the vertical wheel forces. The determination of lateral forces is based on a single-track model. A kinematic Kalman filter, which is independent from any unknown vehicle parameters, is used to estimate the sideslip angle. Using a 3-antenna GPS-receiver the estimation problem can be decoupled into two Kalman filters. The integration of vehicle dynamic sensors and a 3-antenna GPS-receiver enables a high sampling rate and improved accuracy. Based on the state estimation the unknown physical parameters of the wheel force models (such as position of center of gravity, moment of inertia, …) are determined using approximations and least squares parameter estimation.

Development and Evaluation of Tractors and Tillage Implements Instrumentation System

Problem statement: Field machines contribute a major portion of the total cost of crop production. Proper selection and matching of farm machinery is essential in order to reduce the cost of crop production. Performance data for tractors and implements are, therefore, essential for farm machinery operators and manufacturers alike. The aim of this study was to develop and evaluate an instrumentation system for tractor and agricultural implements. Approach: An instrumentation system was developed and mounted on an MF 3090 tractor to measure and record data for the various performance parameters of the tractor and attached tillage implements. The system was designed to measure: drawbar pull, three-point linkage forces, rear and front wheel forces, PTO torque, ground speed, tillage depth, fuel consumption, engine speed and fluid temperatures. Results: The system performed well during the field operations and the results obtained showed that the accuracies of the transducers were acceptable. The wheel torque and weight transducers measured the torque and forces acting on the tractor wheels with high accuracy. The other transducers measured the vertical and the horizontal forces on mounted implements of categories II (40-100 hp) and III (80-225 hp). The field tests showed significant increase in the draft with increases in the depth and speed. A general regression equation to predict draft of the implements was developed. Conclusion: The system was capable of measuring the draft of primary tillage implements on sandy loam soils at various speeds and depths with high accuracy. The data was recorded, displayed and analyzes simultaneously.