Browse Topic: Rack and pinion steering

Items (184)
Find
Extraordinary and Special Purpose Landing Gear SystemsAIR4846B (Current)11/11/2025
A landing gear system comprises the most compelling assembly of engineering skills. Its importance to the successful design of an aircraft can be favorably compared with that of the aircraft's wings and engines. A landing gear system consists of several different engineering disciplines, and is continually in the public eye especially with regard to safety. The primary objective of AIR4846 is to present a record of a variety of interesting gears, gear/aircraft systems and patents, and to discuss wherever possible the lessons learned, and the reasons for the design. Thus, the document is not only a historical account, but a means of recording technical knowledge for the practical benefit of future landing gear designers. Commendable efforts have been made over the years by several individuals to make such recordings, and AIR4846 will make continual reference to them. This applies to all books, papers, or specifications that have the approval of the SAE A 5 Committee. AIR4846 also
A-5B Gears, Struts and Couplings CommitteeNEW
Design and Development of Rack and pinion steering gear assembly for passenger car vehicle2024-26-038501/16/2024
Cross-Helical gears are helical gears with non-parallel,non-intersecting axes and their helix angles are not equal and opposite. Profile shift gears are used to balance the strength of the rack and pinion, avoid undercut, and change the center distance as per the requirement of the vehicle. Passenger cars use these gears for maneuvering by converting the pinion rotary motion to rack translation and thereby turning the wheels. This paper discusses the design and development of Rack and pinion steering (RPS) gear assembly in terms of gear calculations, modeling, performance, and strength analysis over various load cases. Design calculations are being done for several parameters- Normal module, helix angle, No. of teeth as per steering gear ratio and shaft angle. A complete CAD geometry of the RPS gear assembly is made in CAD modeling software UG-NX as per vehicle requirements. BIW and its surrounding parts clearance from the RPS assembly are verified for packaging review. Performance
Rathore, Gopal Singh, chawla, Shubham
Analysis and Annihilation of Grunt Noise in Hydraulic Power Assisted Steering Systems2024-26-021801/16/2024
Hydraulic steering systems employ pressurized fluid to alleviate the effort needed to steer the wheels of an automobile. Hydraulic Power Assisted Systems (HPAS) are cost-efficient, yet intricate. As customer trends lean towards reduced effort and improved handling, HPAS must intervene more in steering, leading to increased pressure requirements from the HPAS pump. Consequently, HPAS components must withstand higher pressure liquid and operate with closer tolerances, occasionally resulting in anomalous functioning. This paper delves into one anomaly with HPAS systems "Grunt Noise", a phenomenon caused by the resonance of the Torsion bar (T-bar) with fluid pressure pulsations. An extensive study was conducted to identify load conditions for grunt noise generation, examine transfer paths and analyze its frequency band. The study also explored the cascading process, reproducing the vehicle-level phenomenon at the rig-level for the Rack and Pinion and later at Pinion Valve assembly level
SETHI, AJITESH, Titave, Uttam, Vardhanan K, Aravindha Vishnu, Zalaki, Nitin, Naidu, Sudhakara
Optimized Variable Gear Ratio Steering System with Reduced EPAS Motor Size achieving Performance Targets 2022-01-106103/29/2022
In electric power assisted steering system (EPAS), the steering assistance torque is provided by the electric motor. The motor rating is decided based on rack force requirement which depends on the vehicle weight, steering gear ratio, wheel angles & turning circle diameter etc. The load on the EPAS motor varies with respect to the steered angles of the road wheels. The motor experiences higher load towards the road wheel lock position. Most of the steering systems used on passenger cars has rack and pinion gear with constant gear ratio (C-factor). The constant gear ratio is decided to create right balance between vehicle handling behavior and steering effort. The constant gear ratio exerts higher steering load which the EPAS motor is required to support up to road wheel lock angles and hence EPAS motor size increases. This paper presents variable gear ratio (VGR) steering system in which gear ratio varies from center towards end lock stroke of rack & pinion. The VGR is optimized in
Kulkarni, Parag Vijay, Salunkhe, Swapnil, Iqbal, Shoaib, Joshi, Nikhil, Shabadi, Nischalkumar
Experimental Analysis of Steering System Moan Noise2021-26-030709/22/2021
Steering system is responsible for providing a precise directional control to the vehicle. The hydraulic power assisted steering system is commonly used in passenger cars and commercial vehicles due to low cost. Power Steering Pump develops and delivers required pressure to provide assistance while steering. It reduces the effort required to steer the vehicle. Steering pump (generally vane type) is a critical part providing hydraulic assistance pressure to rack and pinion/Gear Box. Basically the hydraulic pump noise can be classified as ‘Moan Noise’ and ‘Whine Noise’. The noise generated by power steering pump pressure pulsation is termed as moan and whine based on their frequency. As power train becomes quieter and quieter, it becomes more perceivable at typical engine operating speed range and gives impression of poor refinement and quality. This abstract describes the experimental measurement technique to investigate, analyze, quantify the moan noise and elaborates on design of
Shevate, Hemant Satish, Gosavi, Santosh, Chaskar, Mithun, Pingle, Gautam Ashok, Pawar, Hemant
Crank-Lever Electromagnetic Damper (CLEMD) Design for Automobile Suspension System06-13-01-000202/04/2020
An effective damper is among the most important components of the suspension system. It ensures the right amount of damping force is acting on the suspension system to provide comfort to the passengers and proper road holding to tires. Unfortunately, the energy absorbed by the dampers from the suspension system gets wasted in the form of heat. In this article, it is proposed to use innovative electromagnetic damper (EMD) with a crank-lever mechanism to recover energy from the suspension system. The goal is to develop a lightweight design of EMD that can recover a high amount of power. For the design, an off-road vehicle is used since in off-road vehicles the amount of power wasted in the suspension system is high. Three different design approaches are used, which include single-stage gearbox type, two-stage gearbox type, and three-stage gearbox type of CLEMD. Out of them, the best design, i.e. three-stage gearbox type of CLEMD is selected because of minimum weight and inertia of the
Todmal, Prashant Eknath, Melzi, Stefano
Evaluation of a Robust Haptic Interface for Semi-Autonomous Vehicles12-02-02-000705/15/2019
The advent of steer-by-wire technologies has changed the driving paradigm for drivers and vehicle autonomy. Such technologies integrate electric motors to actuate the tire-road plus human-machine interfaces. Steer-by-wire vehicles can benefit from haptic concepts through the provision of tunable force feedback, coupled with nonlinear control, to introduce lane keeping and pathway following technologies that minimize and possibly eliminate driver actions. In this article, two vehicle haptic interfaces, including a robotic grip and a joystick, both of which are accompanied by nonlinear sliding mode control, have been developed and studied on a steer-by-wire platform integrated with a virtual reality driving environment. An operator-in-the-loop evaluation that included 30 human test subjects investigated these haptic steering interfaces over a prescribed series of driving maneuvers through real-time data logging and post-test questionnaires. A conventional steering wheel with the robust
Wang, Chengshi, Wang, Yue, Wagner, John R.
Aircraft Nosewheel Steering/Centering SystemsAIR1752A (Current)04/17/2019
The intent of this AIR is twofold: (1) to present descriptive summary of aircraft nosewheel steering and centering systems, and (2) to provide a discussion of problems encountered and “lessons learned” by various airplane manufacturers and users. This document covers both military aircraft (land-based and ship-based) and commercial aircraft. It is intended that the document be continually updated as new aircraft and/or new “lessons learned” become available.
A-5B Gears, Struts and Couplings Committee
Use of Cellphones as Alternative Driver Inputs in Passenger Vehicles2019-01-123904/02/2019
Automotive drive-by-wire systems have enabled greater mobility options for individuals with physical disabilities. To further expand the driving paradigm, a need exists to consider an alternative vehicle steering mechanism to meet specific needs and constraints. In this study, a cellphone steering controller was investigated using a fixed-base driving simulator. The cellphone incorporated the direction control of the vehicle through roll motion, as well as the brake and throttle functionality through pitch motion, a design that can assist disabled drivers by excluding extensive arm and leg movements. Human test subjects evaluated the cellphone with conventional vehicle control strategy through a series of roadway maneuvers. Specifically, two distinctive driving situations were studied: a) obstacle avoidance test, and b) city road traveling test. A conventional steering wheel with self-centering force feedback tuning was used for all the driving events for comparison. Based on the lane
Wang, Chengshi, Alexander, Kim, Pidgeon, Philip, Wagner, John
Kinematics and Compliance Analysis of a 3.5 Tonne Load Capacity Independent Front Suspension for LCV2019-01-093504/02/2019
This paper deals with the development of a 3.5 tonne carrying double wishbone front suspension for a low floor LCV. It is a novelty in this class of vehicles. It has a track width of 1810 mm and it has a recirculating ball steering system. The steering mechanism has been arranged so that the steering angle could reach to 48° that is a very effective angle in that vehicle range. This results as a lower turning radius which indicates a better handling for the vehicle. The steering and the front suspension system here have been optimized in terms of comfort and handling by using DOE (design of experiments) based on sequential programming technique. In order to achieve better suspension and steering system geometry, this technique has been applied. The results have been compared with the benchmark vehicle.
Kuris, Salih, Gungor, Efe, Deniz, Ataman, Uysal, Gulsah, Aykent, Baris
Power RACe2019-01-134503/19/2019
Ever increasing process applications inspire us to design innovative and modular manufacturing cells in compliance with modern specifications. The result is the new highly flexible Aerospace application specific robot introduced as the “POWER RACe”. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the Power RACe technology platform.
Dillhoefer, Thorsten, Erdinc PhD, Fatih
Optimizing Steering Column Layout and UJ Phase Angle to Enhance Vehicle Dynamics Performance2019-01-501002/05/2019
Vehicle dynamics is one of the most important vehicle attributes. It is classified into three domains, the longitudinal, vertical, and lateral dynamics. This paper focuses on optimizing the lateral vehicle dynamics which is driven by the straight ahead controllability and cornering controllability of the vehicle. One of the important parameters that dictates these sub-attributes is the steering ratio. Therefore, designing the right steering ratio is critical to meet the vehicle “specific” targets. Significant amount of work has been done by many researchers on variable steering ratio by implementing variable gear ratio (VGR) rack, active steering, and steer-by-wire systems. This paper discusses the methodology and considerations to optimize the steering ratio for a constant gear ratio rack by optimizing the steering column layout, viz., orientation and the phase angle in universal joints. A detailed analysis of steering system layout is done to optimize the steering ratio to enhance
Puvvula, Praneeth, Ravuri, Susheel, Dubal, Ajit, Salunkhe, Swapnil
Steering Control of the Off-Highway Vehicles2019-26-010801/09/2019
Steering is integral system of any vehicle to achieve direction control. With driver’s inputs, as steering wheel is turned, the steering mechanism is operated to turn the road wheels to route the vehicle on desired path. This Paper studies the different steering architectures and the learning is applied to improve the off-highway vehicles’ steering control. Off-Highway vehicles have traditionally been using Hydrostatic Power Steering (HPS) mechanism with no feedback controls. This mechanism consists of inherent limitations to vehicle efficiency, reliability and control preciseness. In this paper, HPS is modeled using 1D simulation tools from the system parameters and derived equations. The results are plotted and discussed to acknowledge the merits and demerits of existing system which helped in proposing the alternate steering solution. Different steering architectures are evaluated and trade-off study performed to choose the Electro-Hydraulic Power Steering (EHPS) architecture. The
Joshi, Bharat, Sukumar, Srikant, Jawale, Vinit, Patil, Ojas
Optimization Control for 4WIS Electric Vehicle Based on the Coincidence Degree of Wheel Steering Centers10-02-03-001107/24/2018
The steering centers of four wheels for passenger car do not coincide, which may result in tire wear and the unharmoniously movement of the vehicle. In this article, an optimization control method for Four Wheel Independent Steering (4WIS) electric vehicle based on the coincidence degree of steering centers is proposed, to improve the driving performance. The nonlinear vehicle model of the four-wheel independent steering vehicle is established, and the formula of the wheel steering center is derived. The coincidence degree of wheel steering centers is defined as the evaluation index, to describe and evaluate the performance of the coordination for wheels’ movement. Meanwhile, the structure design of 4WIS system and the establishment of Direct-Current (DC) steering motor model are carried out, and the Model Predictive Control (MPC) controller for steering actuator is designed. The coincidence degree and related performance index for 4WIS vehicle steering system are performed as the
Zheng, Hongyu, Yang, Shuo
Design, Development and Application of Test Bench for Electrically Controlled Steering Systems2018-01-070204/03/2018
This essay aims to develop an electrically controlled steering test bench and lay a solid foundation for the development of steering system. The first part mainly introduces the function, structure and working principle of the test bench. For the hardware system, it includes the steering system, fixture, sensors as well as a frameless disk motor for carrying out automatic motor input, and a dual linear motor system selected as the road resistance simulation actuator. As for the software, MATLAB/Simulink, CarSim, RTI and ControlDesk are used. Therefore, with the help of real-time simulation platform, researchers can not only build control strategy and dynamic model but also control the experiment and tune parameters in real-time. The second part of the essay aims to identify both electric and mechanical parameters of R-EPS system by carrying out tests on the proposed test bench. As parameters are successfully identified, the feasibility of the test bench is also verified. In the third
Wang, Junyang, Zheng, Hongyu, Zong, Changfu
Control of Steer by Wire System for Reference Steering Wheel Torque Tracking and Return-Ability2018-01-056604/03/2018
This paper proposes a torque tracking algorithm via steer by wire to achieve the target steering feel and proposed a modified friction model to obtain return-ability. A three dimensional reference steering wheel torque map is designed using the measurement data of the steering characteristics of the target vehicle at a transition test and a weave test. In order to track the reference steering wheel torque, a sliding mode control is used in the tracking algorithm. In addition, to achieve return-ability, the modified friction model for steer by wire is used instead of the friction model defined in the reference steering wheel torque map. The modified friction model is composed of various models according to the angular velocity. The angular velocity and the angular acceleration used in the control algorithm are estimated using a kalman filter. A motor is used as the actuators to generate the targeted steering feel and the torque angle sensor (TAS) is used to measure the steering wheel
Lee, Jaepoong, kyongsu, Yi, Kim, Kwangil, Lee, Byungrim, Lee, Dongpil, Jang, Bongchoon, Chang, Sehyun
Steering Shaft Separation with a Collision Involved Heavy Duty Steering Gear2018-01-052404/03/2018
A crash of a medium duty truck led to a study of the failure mechanism of the truck’s steering system. The truck, after being involved in a multi-vehicle vehicle collision, was found with its steering input shaft disconnected from the steering gear. The question arose whether the steering gear failure was a result of the collision, or causative to the collision. An in-depth investigation was conducted into whether forces on the vehicle due to the collision could cause the steering shaft to separate from the steering gear. Additionally, the performance of the steering gear with the adjuster nut progressively backed off was studied to determine the feedback a driver would receive if the steering gear came progressively apart. From the results of these studies, conclusions with regard to the crash causation were reached.
Larson, Robert, Retallack, Charles, Mikhailov, Michael
Multi-Objective Optimization to Improve SUV Ride Performances Using MSC.ADAMS and Mode Frontier2018-01-057504/03/2018
Ride is an important attribute which must be accounted in the passenger segment vehicles. Excessive H point acceleration, Steering wheel acceleration, Pitch acceleration can reduce the comfort of the driver and the passengers during high frequency and low frequency rough road events. Excessive Understeer gradient, roll gradient, roll acceleration and Sprung mass lift could affect the Vehicle driver interaction during Steady state cornering, Braking and Step steer events. The concept architecture of the vehicle plays an important role in how comfort the vehicle will be. This paper discusses how to improve SUV ride performances by keeping handling performance attributes same or better than base vehicle. Multi Objective Optimization was carried out by keeping spring, bushing and damper characteristic as the design variables to avoid new system or component development time and cost. The first step in this process is DOE (Design of Experiments method) which allows to select critical or
Lenka, Visweswara Rao, Anthonysamy, Baskar, Londhe, Abhijit, Hatekar, Harshad
Power RACe2017-01-209309/19/2017
Ever increasing process applications inspire us, as suppliers of aircraft, structural-assembly, and equipment to design innovative and modular, manufacturing cells in compliance with modern specification. The result is the new highly flexible Aerospace application specific robot identified as “POWER RACe”. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the Power RACe technology platform.
Dillhoefer, Thorsten
Quantitative Evaluation of Steering System Rattle Noise2017-28-195207/10/2017
Today’s automotive industry in the process of better fuel efficiency and aiming less carbon foot print is trying to incorporate energy saving and hybrid technologies in their products. One of the trends which has been followed by Original Equipment Manufacturers (OEMs) is the usage of Electric Power Steering (EPS) system. This has been an effective option to target fuel saving as compared to hydraulically assisted power steering system. EPS has been already tested successfully, not only on system level but also on vehicle level for endurance and performance by OEMs as per their norms and standards. Over the decade, NVH (noise, vibration & harshness) have become one of the touch points for customer perception about vehicle quality. This leads us to a commonly perceived problem in EPS or manual type steering system i.e. rattle noise. In this paper, a methodology has been highlighted for detection, identification and measurement of steering rattle noise and hence identifying the noise
Sharma, Utkarsh, Wilson, Simson T., Lalasure, Santosh, Rajakumar, K.
Adaptive Network Trained Controller for Automotive Steering Systems2017-01-962604/11/2017
Electrical Power Assist Steering (EPAS) systems are currently eliminating the traditional hydraulic steering systems in vehicles. EPAS systems are nonlinear Multi Input Multi Output (MIMO) systems with multiple objectives, including fast response to the driver torque command, good driver feel, and attenuation of load disturbance and sensor noises. Optimal control method is employed to design EPAS system controllers for improved performance and robustness. But these controllers have showed acceptable performance for certain operating conditions and undesired steering feel for high steering gain. In this work, the neural networks are used which replace the optimal controllers of EPAS systems. A Euclidean adaptive resonance theory (EART) networks is trained according to the data collected from an H∞ optimal controller. The collected data represent the controller input and output signals. The said data are normalized and clustered into categories in the EART modules. The modules are
Chabaan, Rakaan, Alam, Mohammad Saad
Adaptive Network Trained Controller for Automotive Steering Systems2017-01-9626-TEST-REC04/11/2017
Electrical Power Assist Steering (EPAS) systems are currently eliminating the traditional hydraulic steering systems in vehicles. EPAS systems are nonlinear Multi Input Multi Output (MIMO) systems with multiple objectives, including fast response to the driver torque command, good driver feel, and attenuation of load disturbance and sensor noises. Optimal control method is employed to design EPAS system controllers for improved performance and robustness. But these controllers have showed acceptable performance for certain operating conditions and undesired steering feel for high steering gain. In this work, the neural networks are used which replace the optimal controllers of EPAS systems. A Euclidean adaptive resonance theory (EART) networks is trained according to the data collected from an H∞ optimal controller. The collected data represent the controller input and output signals. The said data are normalized and clustered into categories in the EART modules. The modules are
Chabaan, Rakaan, Alam, Mohammad Saad
Towards a Supermileage Autonomous Vehicle2017-01-011403/28/2017
The project consists on the mechanical and electronic instrumentation of an existing vehicle (built at Universidad de Monterrey for the SAE Supermileage Competition) to be able to control its steering, braking and throttle systems “by wire”. Insight to the stages of turning the vehicle into an autonomous one is presented. This includes identification of the current mechanical properties, choosing adequate components and the use of a simulation to allow early work on the software involving cameras and motors to provide autonomy to the vehicle. Using software in the loop methodology mathematical models of the dynamics of the vehicle are run in Simulink and update the position and orientation of the 3D model of the vehicle in V-REP, a robot simulator.
Lozoya Santos, Jorge De-J., Tudon-Martinez, J. C.
Steering Wheel Torque Control of Steer-by-Wire System for Steering Feel2017-01-156703/28/2017
This paper proposes a reference steering wheel torque map and a torque tracking algorithm via steer-by-wire to achieve the targeted steering feel. The reference steering wheel torque map is designed using the measurement data of rack force and steering characteristic of a target performance of the vehicle at transition steering test. Since the target performance of the vehicle is only tested in nominal road condition, various road conditions such as disturbances and tire-road friction are not considered. Hence, the measurement data of the rack force that reflects the road conditions in the reference steering wheel torque map have been used. The rack force is the net force which consists of tire aligning moment, road friction force and normal force on the tire kingpin axis. A motor and a magnetorheological damper are used as actuators to generate the desired steering feel using the torque tracking algorithm. The torque tracking algorithm is composed of feedforward control and feedback
Lee, Jaepoong, Chang, Sehyun, Kim, Kwangil, Jang, Bongchoon, Lee, Dongpil, Lee, Byungrim, Yi, Kyongsu
Development of Road to Lab Steering Test Rig (ROLAST)2017-26-031501/10/2017
The Steering system is one of the most safety critical systems in an automobile. With time the durability, reliability and the fine-tuning of the parameters involved in this subsystem have increased along with the competitiveness of the market. In a competitive market, accelerated testing is the key to shorter development cycles. It is observed that the majority of component manufacturers have a preference on vehicle level testing to achieve their development goals. The vehicle level trials are time consuming and lack the control and repeat-ability of a laboratory environment. This paper describes the development of a steering test rig designed to simulate the disturbances experienced on road within a controlled laboratory environment. The five axis steering rig would allow simulation of individual road wheel displacement along with steering wheel angle input and lateral steering rack displacements. The rig also is designed to be adaptable to a range of vehicle categories. The rig can
Kale, Jyoti, Kumar, Satish, Lavangare, Pravin, Subramaniam, Anand
A Novel Technique to Establish Various Important Characteristic to Analyze Complete Hydraulic Power Steering System using Model Based Design Approach2017-26-025901/10/2017
Steering system deliver a precise directional control to the vehicle chassis and ensure the safe driving at all maneuvers. Hydraulic power assisted system (HPAS) helps drivers to steer by boosting steering assistance of the steering wheel while retaining the road feel. HPAS performance is associated with the design characteristics of rotary valve, steering, suspension, kinematics, brake, tire, vehicle speed and load transfer. Thus a detailed power steering system model is absolutely necessary to evaluate and optimize the performance characteristics. However, many components of HPAS system are proprietary in nature so it is very challenging to get component characteristic of each sub-system for the complete power steering system model. Hence, it is very important to establish a technique to extract all such influencing characteristics with available test facility. The present study shows a detailed vehicle level HPAS system dynamic model to predict various power steering system
Sawangikar, Sandeep V., Patil, Jeevan N., Palanivelu, Sivakumar, Kumar K, Arun
FRAC (Frame Riveter Assembly Cell)2016-01-207909/27/2016
The industry wide requirement of new highly flexible automated fastening systems in aircraft production has created the need for developing new fastening systems. This paper will focus on the development of the Frame Riveting Assembly Cell (FRAC) by BROETJE-Automation to meet this need. The new FRAC machine configuration is built for automated drilling and fastening of different aircraft type parts. It is highly flexible with a high speed positioning system mounted multifunction end effector. System travel is limited only by installed track length. The FRAC integrates well with conventional and reconfigurable automated fastening work holding tools.
Janssen, Alexander, Dillhoefer, Thorsten
Steering System Noise Evaluation2016-01-183206/15/2016
Intermediate shaft assembly is used to connect steering gear to the steering wheel. The primary function of the intermediate shaft is to transfer torsional loads. There is a high probability of noise propagating through the Intermediate shaft to the driver. The current standard for measuring the noise is by performing vehicle level subjective evaluations. If improperly clamped at either of the yokes, a sudden change in the direction of the torsional load on the Intermediate shaft can generate a displeasing noise. Noise can also be generated from the constant velocity joint. Intermediate shaft noise can be measured using a microphone or can be correlated to acceleration values. The benefit of measuring the acceleration over sound pressure level is the reduction of complexity of the test environment and test set up. The nature of the noise in question requires the filtering of low frequency data. This paper presents a new test procedure that has been developed by General Motors. The test
Kamath, Ramakrishna
Anti-Creep Mechanism Enables Ultra-Precise Motor Table PositioningTBMG-2489406/01/2016
Motion control is essential for the digitization and automation of high-tech equipment, but bearings remain basic to frictionless movement. Bearing Engineers, a bearing distributor, recently changed its name to Motion Solutions (Aliso Viejo, CA) to better reflect their evolution into a custom designer of motion solutions for high-tech electromechanical systems. Developing custom solutions has lead to developing lines of proprietary products that the company manufactures in-house.
Simulation Study on Vehicle Road Performance with Hydraulic Electromagnetic Energy-Regenerative Shock Absorber2016-01-155004/05/2016
This paper presents a novel application of hydraulic electromagnetic energy-regenerative shock absorber (HESA) into commercial vehicle suspension system and vehicle road performance are simulated by the evaluating indexes (e.g. root-mean-square values of vertical acceleration of sprung mass, dynamic tire-ground contact force, suspension deflection and harvested power; maximum values of pitch angle and roll angle). Firstly, the configuration and working principle of HESA are introduced. Then, the damping characteristics of HESA and the seven-degrees-of-freedom vehicle dynamics were modeled respectively before deriving the dynamic characteristics of a vehicle equipped with HESA. The control current is fixed at 7A to match the similar damping effect of traditional damper on the basis of energy conversion method of nonlinear shock absorber. Compared with the vehicle equipped with conventional shock absorber under the same excitation conditions of random road and vehicle speed, vehicle
Peng, Ming, Guo, Xuexun, Zou, Junyi, Zhang, Chengcai
A Novel Electric-Power-Steering (EPS) Control Algorithm Development for the Reference Steering Feel Tracking2016-01-154604/05/2016
This paper describes a reference steering feel tracking algorithm for Electric-Power-Steering (EPS) system. Development of the EPS system with intended steering feel has been time-consuming procedure, because the feedforward map-based method has been applied to the conventional EPS system. However, in this study, a three-dimensional reference steering feel surface, which is determined from current vehicle states, is proposed. In order to track the proposed reference steering feel surface, sliding mode approach is applied to second-order steering dynamics model considering a coulomb friction model. An adaptive technique is utilized for robustness against uncertainties. In order to validate the proposed EPS control algorithm, hardware-in-the-loop simulation (HILS) has been conducted with respect to a typical steering test. It is shown that the reference steering feel is realized well by the proposed EPS control algorithm.
Lee, Dongpil, Jang, Bongchoon, Yi, Kyongsu, Chang, Sehyun, Lee, Byungrim
Effect of Tie Rod Length Variation on Bump Steer2016-28-020102/01/2016
Steering and suspension system has to be designed properly to achieve improved handling characteristics. Improper design of steering systems will result in steering errors such as bump steer and roll steer. These steering errors results in reduced steering performance. During the design of steering system the tie rod length has to be properly selected to reduce these steering errors. The purpose of the work is to analyze the effects of tie rod length variation on bump steer. Multi body dynamic model of the selected vehicle was created using MSC ADAMS Car software. Ideal design of steering system to achieve zero bump steer was created. The tie rod length was later varied up to 10% to study the effect of varying length on bump steer. Parallel wheel travel analysis was conducted to study the tie rod length variation on bump steer. Acceleration test was conducted on a flat road having bump to analyze the effect of changing tie rod length on steering performance of the vehicle. The test
Kulkarni, Upendra, Gowda, Monish M. H., Venna, Hima Kiran
Zero-Gravity Mobile Robot Using ON/OFF Adhesive Pads and Inchworm MechanismTBMG-2366201/01/2016
Inspection of the International Space Station and other manmade objects in space is difficult because of the microgravity environment. Robots are a promising approach to accomplish these inspection tasks and later repairs, but must be able to maneuver across the surfaces. Because there is no gravity, the robot is at high risk of floating away, necessitating grippers that can adhere to the surface and resist the forces and torques of inspecting and moving on the structure.
Custom System Rides the Rails at NASA Radar RangeTBMG-2309810/01/2015
ADC USA, Inc. (Ithaca, NY) develops and supplies high-precision motion systems and instruments for large government laboratories and corporations around the world. ADC was contracted by NASA’s Langley Research Center (Hampton, VA) to design, build, and install the major components for a 40 × 40 × 40-foot indoor radar range. NASA’s goal was to refurbish and upgrade their old indoor radar range. They want to clear out what they had and replace it with newer, better-designed equipment. The goal was to put multiple targets inside the radar range without having to get a forklift to bring them in and out – not only things such as airplanes, but anything that is detected by radar.
Optimisation of Steering System Geometry of Longer FOH Commercial Vehicles2015-01-272109/29/2015
Commercial vehicle industry is presently striving towards development of buses with enhanced passenger safety and comfort. This calls for additional components and aggregates that eventually lead to increase in the overall length and gross vehicle weight (GVW) of the bus for the same passenger capacity. Usually, steering system of longer front overhang (FOH) vehicles have multiple linkages such as bevel box arrangement or intermediate pivot arm arrangement instead of single direct draglink because of packaging and design constraints. In this work, an attempt has been made to design the steering system for one of the longer FOH bus with single direct draglink arrangement. Here, single draglink was packaged and designed with commercially available higher strength tube material. Design optimisation of steering geometry was carried such that the steering performance was atleast on par with existing performance. The MBD analysis has been carried out to compare the performance of existing
Lomada, Balaji, Jayaganthan, R., Vijaykumar, V.
Panel Assembly Line (PAL) for High Production Rates2015-01-249209/15/2015
Developing the most advanced wing panel assembly line for very high production rates required an innovative and integrated solution, relying on the latest technologies in the industry. Looking back at over five decades of commercial aircraft assembly, a clear and singular vision of a fully integrated solution was defined for the new panel production line. The execution was to be focused on co-developing the automation, tooling, material handling and facilities while limiting the number of parties involved. Using the latest technologies in all these areas also required a development plan, which included pre-qualification at all stages of the system development. Planning this large scale project included goals not only for the final solution but for the development and implementation stages as well. The results: Design/build philosophy reduced project time and the number of teams involved. This allowed for easier communication and extended development time well into the project. All
Assadi, Michael, Dobbs, Samuel, Stewart, Brian, Hollowell, Sean, Elsholz, Joseph
Thermoplastic Racks Open Up New Motion Control ApplicationsTBMG-2226706/01/2015
Rack and pinions are linear actuators that play a critical role in a wide range of linear motion control applications. While rack and pinions are commonly thought of as a timeless technology, several new developments have helped provide significant performance improvements in specific applications. One new approach, the Roller Pinion System, replaces the traditional rack and pinion with bearing-supported rollers, increasing positional accuracy, speed and durability.
Automated Floor Drilling Equipment for the 7672014-01-227009/16/2014
A new portable floor drilling machine, the 767AFDE, has been designed with a focus on increased reach and speed, ease-of-use, and minimal weight. A 13-foot wide drilling span allows consolidation of 767 section 45 floor drilling into a single swath. A custom CNC interface simplifies machine operations and troubleshooting. Four servo-driven, air-cooled spindles allow high rate drilling through titanium and aluminum. An aluminum space frame optimized for high stiffness/weight ratio allows high speed operation while minimizing aircraft floor deflection. Bridge track tooling interfaces between the machine and the aircraft grid. A vacuum system, offline calibration plate, and transportation dolly complete the cell.
Rediger, Jason, Malcomb, Joseph, Sylvester, Craig
Steering Kickback Diminution on EHPS for Enhancing Vehicle Ride Comfort and Handling2013-01-289311/27/2013
Electro-Hydraulic Power Steering (EHPS) system is used in modern vehicles to effect reduction in fuel consumption rate and steering effort. The mechanical linkages between the steering wheel and tire, transfers road shocks to steering wheel as high amplitude vibration. This high amplitude vibration causes the steering wheel to deviate from driver intended position. This phenomenon is called steering kickback. The initial objective is to reduce the steering kickback with minimum changes in the vehicle systems. Using check valve is one of the inexpensive and easy operational counter measures. Vehicle level tests were done to evaluate the countermeasure and it was found to have approximately 55 % reduction in kickback. Multi Body Dynamics (MBD) simulation is done using ADAMS/Car to establish the vehicle parameters involve in steering kickback. Full car model was simulated using the experimental conditions and validated. Finally from the simulation, optimized vehicle parameters are
Sundararajan, Rajeshkumar, Natarajasundaram, Balasubramanian, Ramamoorthy, Bhavanakumar, Subramaniam, Thirumalini
An Innovative Design Concept of Four Wheel Steering Mechanism for an Automobile2013-01-284511/27/2013
The main characteristic of vehicle moving on road is related to its response to the drivers command and to environmental factors affecting the direction of motion of vehicle. The two basic problems in handling the vehicle are control of vehicle along the desired path and stabilization of the direction of motion of vehicle against external disturbances. The vehicle with best handling characteristics is the vehicle which can always be controlled by the driver. While parking the vehicle and doing sharp turnings the vehicle with two wheel steering cannot be more significant. The two wheel steering system takes large radius of turning and requires more space to take turn. Hence four wheel steering is preferable than two wheel steering systems. A multi-function four wheel steering system could improve directional stability at high speeds, sharp turning performance at low speeds, and parking performance of a vehicle. Generally there are three types of steering systems which include front
Vanamala, Uma Maheshwar, koganti, Raja Rao
Implementation of Non-Contact Drives into a High-Rail, 7-Axis, AFP Motion Platform2013-01-228809/17/2013
Traditionally, automated fiber placement (AFP) motion platforms use rack and pinion drive trains coupled through a gearbox to a rotary motor. Extensive use of non-contact linear motors on a new AFP motion platform produces a quiet, low-maintenance system without sacrificing precision. A high-rail gantry arrangement allows dynamic performance improvements to machine acceleration and speed, while lowering power consumption costs and capital expenses. The seventh axis incorporated into the machine arrangement effectively produces an effective “five sides of a cube” work envelope, permitting complex spar and panel fabrication.
Ehinger, Peter, Faubion, Guy, Hooks, Joshua, Seever, Luke
Virtual Road Load Data Acquisition using Full Vehicle Simulations2013-01-118904/08/2013
The concept of full vehicle simulation has been embraced by the automobile industry as it is an indispensable tool for analyzing vehicles. Vehicle loads traditionally obtained by road load data acquisition such as wheel forces are typically not invariant as they depend on the vehicle that was used for the measurement. Alternatively, virtual road load data acquisition approach has been adopted in industry to derive invariant loads. Analytical loads prior to building hardware prototypes can shorten development cycles and save costs associated with data acquisition. The approach described herein estimate realistic component load histories with sufficient accuracy and reasonable effort using full vehicle simulations. In this study, a multi-body dynamic model of the vehicle was built and simulated over digitized road using ADAMS software, and output responses were correlated to a physical vehicle that was driven on the same road.
Roy, Nantu, Villaire, Mark
New Light Truck Platform Chassis2013-01-037004/08/2013
The objectives of a new generation of light trucks required the development of a new platform chassis, using advances in packaging, manufacturing efficiency, mass reduction, fuel efficiency, noise and vibration toughness, and ride comfort, while maintaining the vehicle's fun-to-drive character. This paper outlines the chassis component and packaging integration, light weight material application with structural optimization, as well as technical concepts executed to improve performance. Key component focus points are axles and bearings, wheels, tires, suspensions, brakes, engine cradles and sub-frames, steering systems, mechanical controls, and fuel and exhaust systems.
Johnson, Joshua C.
Target Cascading Optimization of the Kinematics of a Steering System Coupled to a Double Wishbone Suspension System of a Hybrid Off-Road Vehicle2013-01-096704/08/2013
Target cascading methodology is applied to the optimization problem of the kinematics of a rack and pinion steering mechanism coupled to a double-wishbone suspension system of a hybrid off-road vehicle. This permits the partition of a complex problem into reduced order sub-problems in a hierarchical manner, leading to a more efficient design and optimization process. According to the nature of the problem, it is proposed a four level hierarchy organization. The uppermost level is the general vehicle design problem. The second level consists in various system-level design problems such as frame, powertrain and the set suspension-steering. The steering system design problem is proposed in a third hierarchical level. At the lowest level are the components design problems. The vehicle under study will work mainly under off-road condition at low speed. Hence, at the steering design problem, two main objectives are searched for optimization: steering performance according to the Ackerman
Blanco, Juan, Munoz, Luis
Research on the Rig Tests for Evaluation of Steering Response of Electric Power Steering(EPS) Sub-System2012-01-192009/24/2012
EPS has now become a compelling technology that nowadays rapidly replacing hydraulic power steering in world market because of its fuel efficiency, sophisticated assist control, additional safety and convenience features. There are various types of EPS such as Column assist type, Pinion assist type and Rack assist type. Small cars with less rack force are equipped with Column or Pinion assist type EPS but for full-sized vehicles with big rack power consumption need Rack assist EPS, what we call R-EPS. Each type of EPS has merits and demerits, but from the perspective of vehicle handling performance, R-EPS has some strong points. And this is why author started this study. Subjective handling evaluation has proven the superiority of R-EPS but objective evaluation was needed. So authors have tried to compare the on center handling characteristics of each EPS on the rig tests and proposed somewhat easy and reliable test method. And by using a design of experiment (DOE) approach, this study
Lee, Seongil, Roh, Eun Ho
Research of the Impact of Power Steering System Parameters on the Vehicle Handling Stability2012-01-025604/16/2012
The characteristic of steering system is extraordinary critical to vehicle handling and stability, and the coulomb friction, which consist of steering gear coulomb friction and kingpin coulomb friction, are usually neglected in the many previous steering system model. In the paper, the dynamic model of hydraulic power steering system (HPS) including 9 rotational degree-of-freedom (DOF) and 1 translational DOF is presented, taking into account coulomb friction of steering system, and the 2-DOF mathematical model is established based on the manipulation of dynamical theory. Then simulation of vehicle handling stability is developed using the model, a goal of investigation of effects of steering ration, stiffness coefficients and moment of inertia of parts on signs of handling and stability involving yaw rate, slip-angle of center of gravity and lateral acceleration. All the work lay good groundwork for designing and selecting of the parameters of steering system.
Liao, ShuHua, Yang, Caihong
“Motion in FEA”: An Innovative Approach for More Physical and More Accurate Vehicle Dynamics Simulation2012-01-076204/16/2012
Vehicle dynamics is a discipline of mechanical engineering that benefited of significant improvements thanks to the progress of computational engineering. Vehicle dynamics engineers are using CAE for the development of a vehicle with MBS and FEA. The concurrent use of these two technologies is a standard in the automotive industry. However the current simulation process is not fully efficient because local geometrical and material nonlinearities are not accurately modeled in classical MBS software. This paper introduces a methodology for vehicle dynamics simulation integrating MBS capabilities in one single nonlinear FEA environment enabling an accurate modeling of nonlinearity in vehicles.
Colsoul, Frederic, Voss, Bernard, Wissart, Thomas
Dynamic Research on Control Strategy of Electric Power Steering System2012-01-021204/16/2012
The developing process of steering system has experienced four phases from the simple mechanical steering system (MS), hydraulic steering system (HPS) to electric-hydraulic steering system (EHPS), till the electric power steering system (EPS) with lower energy consumption and higher performance. EPS has been found of more and more applications in the rapid development of new energy electric vehicles. This paper aims at the dynamic research of the control strategy of EPS system. Through analyzing the simplified structure model of EPS system, the mathematical models of steering wheel-steering shaft, ECU-Assist motor and rack-pinion are established by Newton's second law. The design of curve-line assist curve is one of the main research points, especially the determination method for the function expression of all the segments in the curve-line assist curve. In order to adapt different operating conditions and reduce the side-effect of non-linear factors, three steering control modes and
He, Ziman, Gu, Mengyan
A Large-Scale Robotic System for Depainting Advanced Fighter Aircraft2011-01-265210/18/2011
The general benefits of automation are well documented. Order of magnitude improvements are achievable in processing speeds, production rates, and efficiency. Other benefits include improved process consistency (inversely, reduced process variation), reduced waste and energy consumption, and risk reduction to operators. These benefits are especially true for the automation of the aerospace paint removal (or "depaint") processes. Southwest Research Institute® (SwRI®) developed and implemented two systems in the early 1990s for depainting full-body fighter aircraft at Robins Air Force Base (AFB) at Warner Robins, Georgia, and Hill AFB at Ogden, Utah. These systems have been in production use, almost continuously for approximately 20 years, for the depainting of the F-15 Eagle and the F-16 Falcon fighter aircraft, respectively. Based on these previous systems, the Advanced Fighter Aircraft Depaint System (AFADS) has been designed, built, and installed as part of a large maintenance
Weissling, Dan H., Wiedmann, Stephen L., Solomon, Daniel P.
AIRCRAFT NOSE WHEEL STEERING/CENTERING SYSTEMSAIR1752 (Historical)08/10/2011
This document covers both military aircraft (land-based and ship-based) and commercial aircraft. It is intended that the document be continually updated as new aircraft and/or new "lessons learned" become available.
A-5B Gears, Struts and Couplings Committee
Items per page:
1 – 50 of 184