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Viewing 1 to 30 of 7406
Technical Paper
2014-09-30
Hongyu Zheng, Linlin Wang
The condition of the brake pad wear depends greatly on the distribution of braking force and the type of brakes, so the wear conditions are usually different. From the perspective of braking force distribution, 60% braking force is distributed to the rear axle on a bus, leading to greater wear on the rear axle. While from the perspective of brake types, the brake pad on the front axle will have a greater wear if brake discs are applied to the front axle and drum brakes are applied to the rear axle. Different wear conditions make it impossible to replace all brake pads at the same time, which increases the time and cost needed in repair and maintenance. Both the deceleration of vehicle and optimum distribution of braking force depend on load conditions. The decoration control algorithm of EBS makes the total braking force proportional to the mass of the vehicle, which makes the braking performance independent from the load conditions when using the same pedal operation. Then the total braking force is distributed to each wheel based on the dynamic wheel load to make the adhesion utilization of each axle equal.
Technical Paper
2014-09-30
Dong Zhang, Changfu Zong, Guoying Chen, Pan Song, Zexing Zhang
This paper mainly focuses on the dynamic characteristics and control methods for drive-by-wire electric vehicle. In this paper, the system architecture of the full drive-by-wire electric vehicle is proposed, which vehicle control unit is based on a rapid control prototyping. The X-by-wire electric vehicle is developed with four wheels independently steered, driven by in-wheel motors, braked by electromagnetic brakes and controlled by active suspensions. To identify and classify the drivers’ characteristics, the MDHMM is established by utilizing HMM and Baum-Welch algorithms. A double layer HMM is used to conduct onboard identification according to the driver’s inputs, environmental information and vehicle states. And real-time ideal reference models of vehicle dynamics for different characteristic drivers are built up with RBF neural network technique by using the driving simulator test data, which use dynamics control for the electric vehicle. For a full drive-by-wire electric vehicle, the wheel speed and braking torques of each wheel can be readily obtained.
Technical Paper
2014-09-30
Linlin Wang, Hongyu Zheng
Aimed at enhancing the vehicle safety and improving the braking performance, a slip-rate-based braking force distribution algorithm is proposed for the electronic braking system of combination vehicle. In the algorithm the slip rates of the tractor’s rear wheels and the semi-trailer’s wheels change with the slip rate of the tractor’s front wheels, making tractors’ front wheels lock up ahead of the tractor’s rear wheels and the semi-trailer’s wheels The algorithm can be tested by co-simulation with Matlab/Simulink and Trucksim software on vehicle running both on high and low adhesion roads. The detailed algorithm can be elaborated as follows: The signals of the wheels’ speed and angular acceleration form the sensors are sent to the ECU. In order to simplify the calculating process, the vehicle speed can be evaluated as the maximum of the speeds of the six wheels. A threshold is set for the tractors’ rear wheels and the semi-trailer’s wheels when the slip rates change with the slip rates of the tractors’ front wheels so that the adhesion coefficient can be made best of.
Technical Paper
2014-09-30
Prashant Shinde, Pratik Gore
This paper is an attempt to address and simplify the root cause of catastrophic failures caused by incidents of fire and smoke in commercial vehicles during last few years in China and India. With the advancement of new features in automotive industry, ruinous failures of commercial vehicles, public transport buses have also increased a lot resulting in a considerable number of casualties. Some of the accidents encountered happened because of a crash with fire originating from the fuel tank. An ECU for preventing such fire-mishaps shall be designed for spotting this failure and activating prevention methods in order. It has been observed that the main reason behind these fire-mishaps was burning of fuel tank because of leakage and excessive heat produced due to friction of debris with the fuel tank which happened within a few seconds of the crash. This safety-critical ECU shall process real-time data coming from thermal-sensor and pressure sensor placed on vehicle fuel tank. This real-time data shall be compared with the previously processed values and then the delta-differentiated value shall be used to conclude the likelihood of fire-occurrence.
Technical Paper
2014-09-30
Takahiko Yoshino, Hiromichi Nozaki
It has been reported that steering systems with derivative terms have a heightened lateral acceleration and yaw rate response in the normal driving range. However, in ranges where the lateral acceleration is high, the cornering force of the front wheels decreases and hence becomes less effective. Therefore, we applied traction control for the inner and outer wheels based on the steering angle velocity to improve the steering effectiveness at high lateral accelerations. An experiment using a driving simulator showed that the vehicle’s yaw rate response improved for a double lane change to avoid a hazard; this improves hazard avoidance performance. Regarding improved vehicle control in the cornering margins, traction control for the inner and outer wheels is being developed further, and much research and development has been reported. However, in the total skid margin, where no margin remains in the forward and reverse drive forces on the tires, spinout is unavoidable. Therefore, we applied tire camber angle control to improve vehicle maneuverability in the total skid margin.
Technical Paper
2014-09-30
James Chinni, Robert Butler, Shu Yang
Federal Motor Carrier Safety Requirement (FMCSR) 393.76(h) states that “a motor vehicle manufactured on or after July 1, 1971 and equipped with a sleeper berth must be equipped with a means of preventing ejection of the occupant of the sleeper berth during deceleration of the vehicle.” [1] Today, sleeper berths are equipped with sleeper restraint systems that function to contain the sleeper occupant inside the sleeper berth during reasonably foreseeable crashes. To assess the effectiveness of sleeper restraint systems, computer simulation models of the sleeper cab environment and these restraint systems was developed, with a simulated supine occupant in the sleeper. The model was evaluated using two different rollover crash scenarios. The first rollover scenario used measurements from a previously reported tractor-trailer, driver side leading, quarter-turn rollover crash test. The second rollover scenario was based on reconstruction of a very severe crash that occurred on a mountain road, where a tractor-trailer rolled, passenger side leading.
Technical Paper
2014-09-30
James Chinni, Ryan Hoover
Full-scale vehicle crash testing is an accurate method to reproduce many real-world crash conditions in a controlled laboratory environment. However, the costs involved in performing full-scale crash tests can be prohibitive for some purposes. Dynamic sled testing is a lower cost and widely used method to obtain multiple useful data sets for development of frontal crash mitigating technologies, systems and components. Wherever possible, dynamic sled tests should use vehicle-specific deceleration pulses determined from full-scale vehicle crash tests. This paper establishes a dynamic sled test protocol based on data collected from a small number of full-scale heavy vehicle frontal crash tests. The sled test protocol is intended to be utilized as a basis for building a body of knowledge needed to update heavy vehicle frontal impact test recommended practices. These recommended practices provide direction for the development of frontal crash mitigating technologies, systems and components.
Technical Paper
2014-09-30
Raghuram Krishnamurthy, Rani Mukherjee
Safety compliance has a new set of difficult questions to address due to the usage of COTS, OSS and externally supplied software code in automotive systems. The use of third-party software component is essential to business as it helps in reduction of cost and development cycle. However, there are many technical risks encountered when incorporating Third-Party Software (TPSW) components into safety related software. Moreover, safety systems conforming to new automotive safety standard ISO 26262 are expected to satisfy criteria for co-existence of TPSW with internal safety related software and legacy code. The purpose is to avoid a potential failure that may be triggered by TPSW which in turn may propagate to cause failure in other software partitions. There are several options available to address the above requirements. We should carefully evaluate the TPSW’s functionality and pedigree and apply combination of techniques to assist in supporting the intent of ISO 26262. This paper discusses on the issues concerning insertion of third party software code (OEM supplied code, Tier 2 vendor software) into in-house developed ECU software.
Technical Paper
2014-09-30
Boris Belousov, Tatiana I. Ksenevich, Vladimir Vantsevich, Sergei Naumov
An open-link locomotion module (OLLM) is considered as autonomous energy self-sufficient locomotion setup for designing ground wheeled vehicles of a given configuration including the number of the drive/driven and steered/non-steered wheels with individual suspension and brake systems. The paper concentrates on the module’s electro-hydraulic suspension design and presents results of analytical and experimental studies. The suspension design provides the sprung mass with sufficient vibration protection at low level of normal oscillations, enhanced damping and stabilized angular movements on highly non-even terrain. This is achieved by the introduction of two control loops: (i) a fast-acting loop to control the damping of the normal displacements; and (ii) a slow-acting control loop for varying the pressure and counter-pressure in the suspension system. Thus, two separate but coordinated controls were designed for both loops to act under small (less than ±7 degrees) and big (larger than ±7 degrees) pitch and roll angles of a vehicle designed with a set of the modules.
Technical Paper
2014-09-30
Guoying Chen, Dong Zhang
Four-wheel independent control electric vehicle is a new type of x-by-wire vehicle with four wheels independent steering and four wheels independent drive/brake systems. Due to the superiority of its structure, the vehicle can perform some special actions that conventional vehicles couldn’t complete, such as zero radius turning, oblique driving and crab. These greatly improve the mobility of four-wheel independent control electric vehicles under low speed condition. Furthermore, the vehicle could get better handing stability by the integrated chassis control for steering and drive/braking systems. So in the paper we try to study the integrated chassis control on how to optimally distribute the angles/torque of each wheel of four-wheel independent control electric vehicle that maximizes the used of the friction between tire and road. In order to introduce the vehicle integrated chassis control clearly, this paper is divided into four parts. In part one, the control targets and the hierarchical control structure of the integrated chassis controller are described.
Technical Paper
2014-09-30
Iman Hazrati Ashtiani, Mehrnoosh Abedi
Road trains have been applied as one of the efficient ways for transportation of goods in different countries like United States, Canada, Brazil and Australia. These long vehicles have a wide variety in length or towing systems like fifth wheel or dolly draw-bar and based on specific measured and regulation could be authorized to move in specific roads. In order to avoid hazard and danger in case of accidents of these vehicles, safety performance of a specific type of these vehicles, called B-train, is investigated in this paper. A Multi-Body Dynamics (MBD) model of a B-train, which consists of a prime mover and two trailers coupled by fifth wheels, are simulated in first phase of study. The developed dynamic model is capable of simulating required tests as well as SAE lane change and constant radius turn for roll and yaw stability analysis and safety evaluation. As far as transportation of fuel or other hazardous liquid are a common usage of B-train vehicles, the effects of liquid fill level variation are also considered in this research.
Technical Paper
2014-09-30
Xianjian Jin, Guodong Yin, Youyu Lin
Knowledge of vehicle dynamics variables is very important for vehicle control systems that aim to improve handling characteristics and passenger safety. However for both technical and economical reasons some fundamental data (e.g., Lateral tire-road forces and vehicle sideslip angle) are not measurable in a standard car. This paper proposes a novel Interacting Multiple Model Filter-Based method to estimate lateral tire-road forces by utilizing real-time measurements. The method uses measurements (yaw rate, roll rate, accelerations, steering angle and wheel speed) only from sensors which have already been integrated in modern cars. The estimation method of lateral tire-road forces is based on an interacting multiple model (IMM) filter that integrates in-vehicle sensors of in-wheel-motor-driven electric vehicles to adapt multiple vehicle-road system models to variable driving conditions. Considering extended roll dynamics and load transfer, a four-wheel nonlinear vehicle dynamics model (NVDM) is built.
Technical Paper
2014-09-30
Takahiko Yoshino, Hiromichi Nozaki
In the present paper, we investigate the possibility of improving the maneuverability and stability, e.g., cornering behavior under large lateral acceleration, of vehicles by controlling not only the steer angle but also the camber angle. It possible to improve the marginal performance of vehicle dynamics effect of camber thrust force. In the total skid margin, no margin remains in the tires’ front/rear power regardless of the braking/driving force that is applied, and no performance improvement can be expected. We believe that, by proactively controlling the tire camber angle in relation to the steering angle, we can substantially improve maneuverability and stability in the critical range to a greater degree than with 4WS or direct yaw moment control. In an attempt to improve maneuverability and stability in the critical cornering ranges, the present study focused on negative camber angle control proportional to steering and examined its effectiveness through numerical computations using a tire model, through a camber angle control experiment with a model car, and through a simulation using a vehicle model.
Technical Paper
2014-09-30
Anudeep K. Bhoopalam, Corina Sandu, Saied Taheri
Abstract Safety and minimal transit time are vital during transportation of essential commodities and passengers, especially in winter conditions. Icy roads are the worst driving conditions with the least available friction, leaving valuable cargo and precious human lives at stake. The study investigates the available friction at the tire-ice interface due to changes in key operational parameters. Experimental analysis of tractive performance of tires on ice was carried out indoor, using the terramechanics rig located at the Advanced Vehicle Dynamics Laboratory (AVDL) at Virginia Tech. The friction-slip ratio curves obtained from indoor testing were inputted into TruckSIM, defining tire behavior for various ice scenarios and then simulating performance of trucks on ice. The shortcomings of simulations in considering the effects of all the operational parameters result in differences between findings of indoor testing and truck performance simulations. Thus, the need for state-of-the-art tire-ice models capable of predicting accurate friction levels taking into account all operational conditions becomes evident.
Technical Paper
2014-09-30
Yiting Kang, Subhash Rakheja, Wenming Zhang
Abstract A range of axle suspensions, comprising hydro-pneumatic struts and diverse linkage configurations, have evolved in recent years for large size mining trucks to achieve improved ride and higher operating speeds. This paper presents a comprehensive analysis of different independent front suspension linkages that have been implemented in various off-road vehicles, including a composite linkage (CL), a candle (CA), a trailing arm (TA), and a double Wishbone (DW) suspension applied to a 190 tons mining truck. Four different suspension linkages are modeled in MapleSim platform to evaluate their kinematic properties. The relative kinematic properties of the suspensions are evaluated in terms of variations in the kingpin inclination, caster, camber, toe-in and horizontal wheel center displacements considering the motion of a hydro-pneumatic strut. The results revealed the CL and DW suspensions yield superior kinematic response characteristics compared to the CA and TA suspensions. Toe-in and horizontal wheel center displacements of the CA and TA vary significantly, which could strongly affect the vehicle handling performance and cause greater tire wear.
Technical Paper
2014-09-30
Matt Zwick
Abstract The base design of commercial vehicle wheel end systems has changed very little over the past 50 years. Current bearings for R-drive and trailer wheel end systems were designed between the 1920's and the 1960's and designs have essentially remained the same. Over the same period of time, considerable gains have been made in bearing design, manufacturing capabilities and materials science. These gains allow for the opportunity to significantly increase bearing load capacity and improve efficiency. Government emissions regulations and the need for fuel efficiency improvements in truck fleets are driving the opportunity for redesigned wheel end systems. The EPA and NHTSA standard requires up to 23% reduction in emissions and fuel consumption by 2017 relative to the 2010 baseline for heavy-duty tractor combinations. This paper summarizes the history of current wheel end bearing designs and the opportunity for change to lighter-weight, cooler-running and more fuel-efficient wheel bearing designs to help meet the new industry standards.
Technical Paper
2014-09-30
Joshua L. Every, M. Kamel Salaani, Frank S. Barickman, Devin H. Elsasser, Dennis A. Guenther, Gary J. Heydinger, Sughosh J. Rao
Dynamic Brake Support (DBS) is a safety system that has been applied to various passenger cars and has been shown to be effective at assisting drivers in avoiding or mitigating rear-end collisions. The objective of a DBS system is to ensure that the brake system is applied quickly and at sufficient pressure when a driver responds to a collision imminent situation. DBS is capable of improving braking response due to a passenger car driver's tendency to utilize multi-stage braking. Interest is developing in using DBS on commercial vehicles. In order to evaluate the possible improvement in safety that could be realized through the use of DBS, driver braking behavior must first be analyzed to confirm that improvement is possible and necessary. To determine if this is the case, a study of the response of truck drivers' braking behavior in collision imminent situations is conducted. This paper presents the method of evaluation and results. Data was drawn from a prior NHTSA simulator study and showed that many drivers exhibited multi-stage braking during four different imminent crash scenarios.
Technical Paper
2014-09-30
Marius-Dorin Surcel, Yves Provencher
Abstract The objective of this project was to compare the fuel consumption and traction performances of 6 × 2 and 6 × 4 Class 8 tractors. Two approaches have been considered: evaluation of 6 × 2 tractors, modified from 6 × 4 tractors, and evaluation of OEM 6 × 2 tractors. Compared to the 6 × 4 tractors, which are equipped with a rear tandem with both drive axles, the 6 × 2 tractors have a rear tandem axle with one drive axle, and one non-drive axle, also called dead axle. The 6 × 2 tractor configurations are available from the majority of Class 8 tractor manufacturers. The SAE Fuel Consumption Test Procedures Type II (J1321) and Type III (J1526) were used for fuel consumption track test evaluations. Traction performances were assessed using pull sled tests to compare pulling distance, maximum speed, and acceleration when pulling the same set sled on similar surface. Fuel consumption tests showed that 6 × 2 tractors consume up to 3.5% less than the similar 6 × 4 tractors, whilst pull sled tests showed shorter distance, lower maximum speed, and lower acceleration for the 6 × 2 tractors, when compared to similar 6 × 4 tractors.
Technical Paper
2014-09-30
Hongyu Zheng, Linlin Wang
Abstract At present, the active safety and stability of heavy vehicles have becoming big concern among the road transportation industry. The purpose of this paper is to specify the research stability and safety of heavy vehicles those set up the accurate and reliable dynamic vehicle reference model and search the method to improve the stability and safety of tractor and semitrailer. A Multi-objective control algorithm was studied to differential braking based on linear quadratic regulator (LQR) control method. Simulation results show that the multi-objective control algorithm can effectively improve the vehicle driving stability and safety.
Technical Paper
2014-09-30
Hongyu Zheng, Linlin Wang
Abstract The active safety and stability of tractor and trailer (heavy-duty vehicle) have becoming big concern among the road transportation industry. The purpose of this paper is to specify the research differential braking force distribution control algorithm to improve braking safety of heavy-duty vehicle. The ideal braking force of each wheel axle should be proportional to vertical load of vehicle that is also related to the road adhesion coefficient, the load and the braking intensity. Reasonable braking force distribution can enhance its braking stability and shorten the braking distance by making full use of the road adhesion condition of each wheel. A braking force distribution algorithm is proposed, in which the objective braking force change with the axle load of vehicle. A controller is built with Matlab® software and TruckSim® software on vehicles respectively equipped with electric braking system (EBS) on typical condition and the simulation results show that the control strategy can shorten the braking distance and improve vehicle safety.
Technical Paper
2014-09-30
Can Wang, Gangfeng Tan, Bo Yang, Ming Chen, Fudong Wei, Yabei Ni
Abstract The hydraulic retarder, which is an auxiliary brake device for enhancing traffic safety, has been widely used in kinds of heavy commercial vehicles. When the vehicle equipped with the retarder is traveling in non-braking state, the transmission loss would be caused because of the stirring air between working wheels of the rotor and the stator no matter if the retarder connects in parallel or in series with the transmission [1]. This paper introduces an elaborate hydraulic retarder air-friction reduction system (AFRS) which consists of a vacuum generating module and pneumatic control module. AFRS works to reduce the air friction by decreasing the gas density between working wheels when the retarder is in non-braking state. The pneumatic control model of hydraulic retarder is built first. Then various driving conditions are considered to verify the performance of the AFRS. The stability of the AFRS is analyzed based on the complete driveline model. And the vacuum power of AFRS and the air-friction of retarder are analyzed comprehensively.
Technical Paper
2014-09-30
Sunil Raj, S Ravi Shankar
Abstract Automotive component light weighing is one of the major goals for original equipment manufacturers (OEM's) globally. Significant advances are being made in developing light-weight high performance components. In order to achieve weight savings in vehicles, the OEM's and component suppliers are increasingly using ultra-high-strength steel, aluminum, magnesium, plastics and composites. One way is to develop a light weight high performance component through multi material concept. In this present study, a bimetal brake drum of inner ring cast iron and outer shell of aluminum has been made in two different design configurations. In two different designs, 40 and 26% weight saving has been achieved as compared to conventional gray cast iron brake drum. The component level performance has been evaluated by dynamometer test. The heat dissipation and wear behavior has been analyzed. In both designs, the wear performance of the bimetal brake drum was similar to the gray cast iron material.
Technical Paper
2014-09-30
Dhiraj Dashrat Salvi
Braking system is having a key importance in vehicle safety & handling stability. In this research paper I had developed a circuit model of Antilock braking system where the operating medium is hydro-pneumatic. A solenoid operated modulator valve consisting of two 2/2 valves is connected in line with the air cylinder & hydraulic master cylinder assembly. Using methodology of response time calibration time taken to modulate hydraulic pressure against pneumatic pressure is evaluated. The signal input to the modulator valve is given by the Electronic controlled unit (ECU). All results obtained is exported to an excel file using Data Acquisition software with pressure myograph system. It gives easy and intuitive readings based on the signal program from ECU for various inputs (i.e. ramp, step). The signals are program for various inputs in order to check the fidelity of the circuit. These readings are easily customized to get the optimum graphs. The response time evaluated from the calibrated data is compared with benchmark or standard set by central motor vehicles rules (CMVR) to meet the regulation.
Technical Paper
2014-09-30
Dong Zhang, Changfu Zong, Ying Wan, Hongyu Zheng, Wei-qiang Zhao
Abstract Electronic braking system (EBS) of commercial vehicle is developed based on Anti-lock Braking System (ABS), for the purpose of enhancing the braking performance. Based on the previous study, this paper aims at the development and research on the control strategy of advanced electronic braking system for commercial vehicle, which mainly includes braking force distribution and multiple targets control strategy. In the study of braking force distribution control strategy, the mass of vehicle and the axle loads will be calculated dynamically and the braking force of each wheel will be distributed regarding to the axle loads. The braking intention recognition takes the brake pad wear into account when braking uncritically, so it can detect a difference in the pads between the front and the rear axles. The brake assist strategy supports the driver during emergency braking and the braking distance is shortened by the reduction of the braking system response time. In the multiple targets stability control algorithm, a simplified vehicle model, a Kalman filter estimator and an Adaptive Kalman filter estimator of heavy duty vehicles are built, by which the parameters and states can be estimated successfully.
Technical Paper
2014-09-28
Veronika Mayer, Brian Richards
Abstract Fierce competition demands more and more consideration for raw materials that are price competitive without the sacrifice of technical results. High and very often fluctuating raw material costs and availability challenge and complicate the calculation for brake pads raw materials. Therefore there is a strong demand for raw materials with high technical performance at stable predictable costs. For these reasons micaceous Iron Oxide (MIO) is evaluated. A case study describes the substitution of two well-established materials Zirconium Silicate and Potassium Titanate by micaceous iron oxide MIO in disk brake pads. MIO is a naturally occurring mineral with lamellar particle shape. The study compares the addition of 3 wt-% and 6 wt-% of Zirconium Silicate, Potassium Titanate and of MIO in a low-metallic formulation for disk brake pads. Regarding technical performance several properties are evaluated. Tests for friction coefficients are carried out according to the AK-Master SAE J2522.
Technical Paper
2014-09-28
Axel Stenkamp, Michael Schorn
Abstract Starting in the late '90s, a new and innovative brake disk technology entered the high performance passenger car market. Approx. 2 years later, small volume production of carbon-ceramic brake disks started. In the past ten years the number of cars equipped with the new generation of ceramic matrix composite (CMC) brake disks has continuously increased, with main usage in low volume, high horse power applications. The goal of this paper is to give an overview of the system specific boundary conditions as well as today's and tomorrow's targets and aspects of friction material development used in CMC-disk based brake systems. Starting with a description of the system component properties, a comparison of typical CMC vs. standard gray cast iron disk (GCI) applications will be made. The impact of the component properties, especially the disk as friction counterpart to the pad, will be shown by comparing industry standard test scenarios. One described system boundary will be the thermal load to the brake pad.
Technical Paper
2014-09-28
Mithun Selvaraj, Suresh Gaikwad, Anand Kumar Suresh
Abstract The highest goal for a good brake system design must be that the vehicle when braking obtains a shorter stopping distance does not leave the track and remains steerable. From the perspective of road traffic, safety and for avoidance of accidents the time and location of a vehicle coming to halt after braking are crucial. In heavy commercial vehicle having longer wheel base, pneumatic brake system is being used.The pneumatic brake system configuration has to be designed in such a way that the response time should meet the safety regulation standards and thereby achieve shorter stopping distance and vehicle stability. Validating the effectiveness of pneumatic brake system layout experimentally on stopping distance and vehicle stability is expensive. This paper deals with the modeling of a typical heavy commercial vehicle along with the entire pneumatic brake system layout with actuating valves, control valves and foundation brakes to predict the dynamic behavior and stopping distance.
Technical Paper
2014-09-28
SeongJoo Lee, JooSeong Jeong, ShinWook Kim, ShinWan Kim, Seong Rhee
A previous investigation showed that minor variations in alloying elements in gray cast iron disc contributed to measurable differences in friction and disc wear. This investigation was undertaken to find out if and how the increased friction and disc wear might affect brake squeal. The SAE J2522 and J2521 dynamometer procedures as well as an OEM noise dynamometer procedure and a chassis dynamometer noise procedure were used to find out if a correlation between disc wear and brake squeal could be discovered. In all cases, as the wear rate of a disc increases under a given set of test conditions, disc material transfer to the pad surface increases, which results in increased friction and brake squeal. Also a good method to detect disc variability (disc to disc, within a disc) is discussed.
Technical Paper
2014-09-28
Shiwalik Ghosh, Baskar Anthonysamy, Ravi Kaushik
Prevailing cut-throat competition in Indian Two wheeler segment confronts to enhance performance of traditional braking system with reduction in cost and weight as substantial consideration. The need of the hour requires subjecting the braking system to variable parameters to achieve progress in minimizing Stopping distance and increasing Mean Fully Developed Deceleration (MFDD). The purpose of this study is to augment the braking performance of two wheeler segment by comparing various combinations of twin leading drum brake layouts by method of Virtual Simulation. The conventional drum brake system utilizes one cam, one pivot, one leading shoe member and one trailing shoe member. In the event of braking, leading shoe causes the generation of drag force. The other shoe is "trailing", moving against the direction of rotation, is thrown away from the friction surface of the drum and is far less effective. The present study highlights the incorporation and enhancement of braking characteristics of bigger brake drum system into smaller brake drum system through the adoption of Twin Leading Shoe (TLS) concept with the added advantage of reduction in cost.
Viewing 1 to 30 of 7406