Chassis System Research Articles

OSEK OS 기반 ACC/LKS 통합제어기 구현

Abstract This paper implements an integrated vehicle chassis system of ACC(Adaptive Cruise Control) and LKS(Lane Keeping System) based on OSEK OS to vehicle operating system and analyzes its performance through experiments. In recent years active safety and advanced driver assistance system has discussed to improve safety of vehicle. Among the rest, We integrate ACC that controls longitudinal velocity of vehicle and LKS that assists a vehicle in maintaing its driving lane, then implement integrated control system in vehicle. Implemented control system uses OSEK/VDX proposed standard, which is aiming at reusability and safety of software for vehicle and removal hardware dependence of application software. Redesigned control system based on OSEK OS, which is supported by OSEK/VDX, can manage real-time task, process interrupt and manage shared resource. We show by results performed EILS(ECU-In-the-Loop Simulation) that OSEK OS-based integrated controller of ACC and LKS is equivalent conventional integrated controller of ACC and LKS.

Simulation Research on an Electric Vehicle Chassis System Based on a Collaborative Control System

This paper presents a collaborative control system for an electric vehicle chassis based on a centralized and hierarchical control architecture. The centralized controller was designed for the suspension and steering system, which is used for improving ride comfort and handling stability; the hierarchical controller was designed for the braking system, which is used for distributing the proportion of hydraulic braking and regenerative braking to improve braking performance. These two sub-controllers function at the same level of the vehicle chassis control system. In order to reduce the potential conflict between the two sub-controllers and realize a coordination optimization of electric vehicle performance, a collaborative controller was built, which serves as the upper controller to carry out an overall coordination analysis according to vehicle signals and revises the decisions of sub-controllers. A simulation experiment was carried out with the MATLAB/Simulink software. The simulation results show that the proposed collaborative control system can achieve an optimized vehicle handling stability and braking safety.

日本自動車研究所における自動車排出ガス試験設備 -大型車用シャシおよびエンジンダイナモメータシステム

日本自動車研究所における自動車排出ガス試験設備 -大型車用シャシおよびエンジンダイナモメータシステム

Research and Design of a Novel Mobile Police Station

By studying the design theory of the mobile police station (MPS), the dynamic model of the MPS basic computing has been built then a novel MPS is designed. This kind of MPS, which consists of battery, chassis, body and electrical system, uses electric vehicle as the carrier and in combination with police needs is equipped with a variety of police equipment to meet the needs of establishing a modern police. The vehicle performance test has been done. The results prove that the performance of the MPS has reached the technical level of the Ministry of Science and Technology, showing the vehicle design is reasonable, and the matching calculation results of the electrical system parameters are basically the same as the experimental results.

Vehicle Active Chassis Integrated Control Based on Multi-Model Intelligent Hierarchical Control

According to the characteristics of the vehicle active chassis system, multi-model system including Electric Power Steering System (EPS), Anti-lock Braking System (ABS) and Semi-active Suspension system (SAS) is established. Then, using the strategy of intelligent hierarchical control, the coordinated controller of active chassis system is designed. The bottom layer controller includes 3 separate controllers, i.e., suspension, steering and braking system controllers. They are used to carry out different control tasks and achieve performance indexes of subsystems. The upper layer coordinated controller is used to judge the vehicle states. At the same time, combined with the vehicle chassis coordinated control logic and the characteristics of feed-back information coming from the bottom controllers, the upper coordinated controller make whole coordination and control decision-making to vehicle active chassis subsystems. The simulation results show that the intelligent hierarchical control can improve the vehicle operational performances effectively.

Parameter Mapping Method for Multi-System Design of Automotive Chassis

Automotive chassis is an engineering system whose successful design requires harmonization of a number of objectives and constraints that, in principle, can be modelled as a constrained multidisciplinary design optimazation in the space of design variables. However, accurate recognition and effective management of coupling relationships among multisystem design models is fundamental to implementation of Multisystem Design. In view of the demand of complex automotive chassis system design, A model of multidisciplinary design optimazation(MDO) is built. Subsequently, The genetic algorithm is used for parameter recognition and representation among multidisciplinary model solvers (design systems). The parameter mapping approach enables integration of coupled disciplinary model solvers, and effective accelerates coordination of multidisciplinary computation processes. The parameter mapping approach has been applied to automotive chassis design, and which significantly improves the efficiency and quality of design.

Research on Coordinated Control of the Vehicle Chassis System Based on a Hybrid Model

Based on the analysis of the movement relationship among systems such as the chassis suspension and the steering and braking system, simulation and testing are carried out on control system of the vehicle chassis system with a coordinated control method of the hybrid model. For the complex vehicle chassis system, modeling and simulation focuses on the movement effects of the three subsystems, classifying complex under different conditions by control methods and testing control parameters separately. Based on the simulation results of the vehicle and the parameters of the controllers, software & hardware systems of the vehicle are designed, and the tests of the vehicle chassis system are carried out based on the hybrid model. The results indicate that under complicated conditions, control systems with the hybrid model can effectively improve the ride comfort, handling, and security.

Coordinated Control of Vehicle Chassis System Based on Game Theory and Function Distribution

Considering the coupled dynamics among suspension,steering and braking sub-systems in vehicle chassis,the high-order and nonlinear dynamic model is built.The sub-optimal controllers of nonlinear H∞ control,direct yaw moment PID control and sliding mode control are separately designed for the suspension,steering and braking subsystems.In order to further improve the vehicle chassis whole-region optimal control performance,the subsystems' control functions are distributed based on the function distribution principle,and the subsystem's control function indices are utilized for competing by game theory.The upper-layer coordinated controller is designed to obtain the expected control output values,and the fuzzy rules are utilized to adaptively adjust the subsystems' control output in order to follow the whole-region control object.The considerable simulations are carried out for full-vehicle coordinated control system,and the function distribution based chassis control system test platform is established by utilizing ARM in order to carry out the vehicle road test.The results demonstrate that the full-vehicle coordinated control system based on game theory can obtain the best control performances than the uncoordinated control system and uncontrolled system.

EMB 시스템의 모델 기반 센서 고장 검출 알고리즘 개발

The brake-by-wire technology is a new automotive chassis system that allows standard braking operations by electronic components with lighter weights and faster response. The brake-by-wire units such as EMB (Electro-Mechanical Brake) are controlled by electronic sensors and actuators and, thus, the fault diagnosis is essential for implementation. In this study, a model-based fault diagnosis system is developed for the sensors based on the analytical redundancy method. The fault detection algorithm is verified in simulations for various faulty cases. A test bench is built including the EMB unit and the performance of the proposed fault diagnosis system is evaluated through the experiment.

Investigation of the wear behaviour of polyacetal bushings by the inflow of contaminants

Polyacetal is used as a part of the lower arm ball joint in the automobile chassis system. It is used as the bushing material, which is in contact with the steel ball on stud under the grease-lubricated condition. In an automobile chassis system, environmental factors reduce the durability of the automotive components. While driving, the grease is contaminated with dust particles and water. Introduction of the dust particles and water into the ball joint increases the wear of the bushing. The damage or the failure of the ball joint can generate noise and lead to uncomfortable driving conditions. Also, it will reduce the durability of other components in the chassis system. Since the ball joint is directly exposed to external environments, it is necessary to investigate the effect of contaminants on the wear of the bushing. In this study, the wear behaviour of the polyacetal bushing for inflow of dust particles and water were investigated. The ball-on-disk type wear test was used for the sliding tests. The disk specimen was made with polyacetal material and the ball specimen was made with steel. The wear volume increased with the amount of the dust particles up to 1.5 g/10 ml and then decreased. The surface was covered with the dust particles, so the dust layer had to be removed to further wear out the surface. The wear volume increased with the amount of the water. When grease was contaminated with water, a water layer, instead of the grease layer, formed on the surface during sliding.

Effect of Dust Particle Inflow on the Wear of Rubber Seal Material in Automobile Chassis System

In an automobile chassis system, several environmental factors reduce the durability of automotive components. In particular, dust particles entering through rubber seals increase the friction and wear of sliding surfaces. Increased wear causes noise, fracture, and reduced service life of components. In this study, dust particles were collected on the chassis while driving. The particle sizes and ingredients of the dust were analyzed using microscopy, scanning electron microscopy, and energy-dispersive X-ray. It was found that SiO and AlO were the main ingredients of the dust particles. Based on our analysis of the data, wear tests were performed with the rubber seal specimens using a ball-on-disk type sliding wear tester. When SiO and AlO particles came into contact with the rubber seal specimen, two-body and three-body abrasive wear took place. In tests of SiO particles only, the wear volumes of rubber seal specimens were increased by increasing the particle's injection amount and the size of the dust. In a test of the mixed particles (SiO and AlO), four mixing ratios (8:1, 4:1, 2:1, 1:2 [SiO:AlO]) were used based on the analysis data. When the same size particles of SiO and AlO were used, the wear amounts of the rubber increased with a higher percentage of AlO, which is harder than SiO. When mixed particles with 26.6 μm of SiO and 1 μm of AlO were used, wear increased with increased amounts of SiO.

Steering pull and drift considering road wheel alignment tolerance during high-speed driving

This paper describes an analytical vehicle model and a full-vehicle model that consider the effect of suspension geometry on steering pull and drift. Steering pull occurs when a driver applies steering wheel torque to keep a straight-line course, and steering drift means the tendency to deviate from the intended path with a free steering wheel. In designing a chassis system, it is crucial to establish a suspension insensitive to steering pull and drift regardless of manufacturing tolerances. Simulation results show that larger caster trail at the front wheel leads a less-sensitive vehicle towards steering pull and drift, since caster trail reduces the equilibrium slip angle difference between pull and drift by considerably changing the aligning moment diagram. These wheel alignment sensitivities are validated by experimental measurement of drift distance.

Research on vehicle chassis system using Layered Coordinated Control strategy

A Layered Coordinated Control (LCC) strategy for chassis system that is divided into upper and bottom layer control parts is proposed. The bottom controllers are made up of three separate controllers, i.e. suspension, steering and braking systems. Each of them is used to carry out different control tasks and to achieve performance indices of subsystems. The Upper Coordinated Controller receives information coming from chassis system and modifies the decision-making of bottom controllers, aiming at improving whole vehicle synthesis performance. To demonstrate the performance of our proposed method, it is implemented under the MATLAB/SIMULINK software environment, and the simulation results show that chassis system based on LCC strategy is able to achieve better ride comfort, more security and higher handling stability than that of the commonly used single layered control one.

Miami Redblade III: A GPS-aided Autonomous Lawnmower

This paper describes the technical aspects of the Redblade III, Miami University's third generation autonomous lawnmower. The Redblade III was created for entrance in the Institute of Navigation's 4th Annual Autonomous Lawnmower Competition by a team of undergraduate students majoring in electrical, computer, and mechanical engineering at Miami University. This paper details the five major subsystems of the lawnmower, including (1) the sensing system, (2) the control system, (3) the mechanical chassis system, (4) the safety system, and (5) the base monitoring and testing system. The paper discusses each aforementioned system in detail, along with providing cost analysis and conclusions.

Vehicle chassis system based on layered coordinated control

A layered coordinated control strategy for chassis control system which is divided into upper and bottom layer control parts is adopted. The bottom controllers are 3 separate controllers, i.e., suspension, steering and braking system controllers. The controllers are used to carry out different control tasks and achieve performance indexes of subsystems. Based on layered coordinated control strategy, the upper coordinated controller is used to receive decision-making information coming from bottom controllers and modify the decision-making of bottom controllers, aiming at improving whole vehicle synthesis performance. The simulation and experimen-tation results show that chassis system control based on layered coordinated control achieves better performances of ride comfort, security and maneuver stabilization.

The design of a chassis system based on multi-objective qLPV control

In this paper we compare LTI and qLPV H_infty H_2 controllers. The Pareto limit is used to show the compromise that has to be done when a mixed synthesis is achieved. Simulations on a nonlinear half vehicle model, with multiple objectives, are performed to show the efficiency of the method.

DEVELOPING AREMA ROAD PROFILE MODELS WITH A STATIONARY RESIDUAL PROCESS

The principal excitation to a vehicle's chassis system is the road profile. Simulating a vehicle traversing long roads is impractical and a method to produce short roads with given characteristics must be developed. An autoregressive model of non-stationary road profile data has been developed previously. This work examines the residual process of such an ARIMA model. Statistical techniques are developed and used to examine the distribution of the residual process and the preliminary results are demonstrated. Implications of this work to characterizing road profiles and future studies are discussed.

En Route to a Motorized Nanocar

[structure: see text] With the eventual goal of demonstrating a motorized nanocar, the key structure has been synthesized which bears a light-activated unidirectional molecular motor and an oligo(phenylene ethynylene) chassis and axle system with four carboranes to serve as the wheels. Kinetics studies in solution show that the motor indeed rotates upon irradiation with 365 nm light, and the fullerene-free carborane wheel system is an essential design feature for motor operation.

P-70: A New Chassis Design Concept for Plasma Display Panels

Plasma display panel (PDP) manufacturers are motivated to reduce costs to broaden consumer acceptance and to fend off competition from other flat panel and projection display technologies. This paper introduces a novel approach to designing the plasma display panel chassis that represents the lowest cost and lightest weight chassis system in the industry while significantly reducing the average screen temperature compared to conventional chassis designs. The new chassis design is enabled by the use of a natural graphite based thermal spreader sheet that renders redundant the thermal spreading function of the solid aluminum chassis.

Modeling and simulation of hydraulic components for passenger cars

Passenger car suspensions contain a number of hydraulic components, such as dampers, hydraulic rubber mounts, power steering and active suspension units. Modeling and simulation of these hydraulic components is reviewed and further developed on the basis of one-dimensional flows represented in the time domain, which is an effective and reliable approach for the design and analysis of automotive fluid power systems. The components of suspension systems are assembled by multi-port connectors for numerical analysis. Then, the solution by standard integration codes may result in fluid mass losses, which do not exist in reality. Therefore, an implicit integration code conserving the fluid mass is presented. The validated hydraulic component model blocks can be exported to a wide range of simulation programs without encountering problems. An active tire tilt control (ATTC) system is presented in detail. The deployment of automotive fluid power simulation allows for suspension system and vehicle dynamics design in virtual reality before a prototype vehicle is built. It is shown that accurate component models are required as a sound basis for the process chain of modeling, validation, and parameter identification, which results in full vehicle simulation. The excellent performance of ATTC vehicles has proven the quality of the predictive simulation results used for the performance optimization of this chassis system.