A Prototype Steering Weave Stabilizer for Automobiles

1991 ◽  
Vol 113 (1) ◽  
pp. 138-142 ◽  
Author(s):  
J. C. Whitehead
Keyword(s):  
High Speed ◽  
Steering System ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Phase Lag ◽  
Vehicle Speed ◽  
Control Torque ◽  
Concentrated Mass ◽  
Wheel Rim ◽  
The Difference

A prototype high-speed steering stabilizer for automobiles applies transient steering torques so that the sum of natural steering restoring torque and the control torque is more nearly in phase with steer angle than the natural restoring torque alone. The resulting reduction in the phase lag from steer angle to restoring torque mitigates the steering weave mode. Since steering restoring torque is nearly proportional to vehicle lateral acceleration, weave controller circuitry could subtract instantaneous lateral acceleration from expected steady-state lateral acceleration calculated from steer angle and vehicle speed, and thence command a steering torque actuator depending on the difference signal. The prototype performs the same function using a concentrated mass on the lower steering wheel rim which is passively sensitive to both steer angle and lateral acceleration, thereby applying only transient steering torques in the desired manner at a vehicle speed of 30 m/s. The additional steering system inertia alone affects the weave mode, so a non-stabilizing configuration with the same mass distributed around the steering wheel rim is tested for direct comparison. The experimental data show a dramatic stabilization of weave for the configuration which applies control torque.

Research of Electric Power Steering System Assistance Characteristic Based on the Identification of the Road

2013 ◽  
Vol 756-759 ◽  
pp. 4401-4406 ◽  
Author(s):  
Qiang Li ◽  
Chang Gao Xia
Keyword(s):  
Characteristic Curve ◽  
Steering System ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Analysis Model ◽  
The Road ◽  
Power Steering ◽  
Resistance Torque ◽  
Wheel Torque ◽  
The Difference

Study of traditional assist characteristic cure does not take into account the difference of steering resistance torque caused by different road adhesion coefficient. Vehicle dynamics analysis model is established based on ADAMS/CAR. Simulation of steering wheel torque is realized under different road conditions. Departure from the ideal boost characteristics requirements and combined with ideal steering wheel torque under different speed and lateral acceleration., the article built assist characteristic curve under a certain road conditions. The system can real-time select the assist characteristic curve through identifying the vehicle traveling road conditions by the way of BP neural network. The theory provided a feasible method for the improvement of the EPS system performance.

Variable steering ratio control of steer-by-wire vehicle to improve handling performance

2019 ◽  
Vol 234 (2-3) ◽  
pp. 774-782
Author(s):  
Xiaodong Wu ◽  
Wenqi Li
Keyword(s):  
High Speed ◽  
Objective Evaluation ◽  
Angular Speed ◽  
Steering System ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Handling Performance ◽  
Steer By Wire ◽  
Fuzzy Neural ◽  
Lane Change Test

To improve vehicle handling performance, a variable steering ratio characteristic for steer-by-wire system is designed. The steering ratio is adjusted by a compensating coefficient according to vehicle longitudinal speed and steering wheel angle. To evaluate the performance of vehicle with variable steering ratio, simulations are conducted based on an objective evaluation index, which consists of quadratic cost functions of vehicle lateral deviation, steering angular speed, vehicle lateral acceleration and roll angle. By using the optimized data from the simulation results, a Takagi-Sugeno fuzzy neural network is designed for the steering ratio control. In order to test and validate the proposed controller, a series of comparison experiments are conducted on a closed-loop driver-vehicle system, including lemniscate curve test and double lane-change test. The results demonstrate that compared with a conventional steering system with fixed steering ratio, the proposed system can not only improve steering agility at low speed and steering stability at high speed, but also reduce driver’s workload in critical driving conditions.

Steering Analysis of Multi-Axle Vehicle Based on ADAMS/VIEW

2012 ◽  
Vol 538-541 ◽  
pp. 2878-2881
Author(s):  
Yong Qiang Zhu ◽  
Ping Xia Zhang
Keyword(s):  
High Speed ◽  
Large Angle ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Low Speed ◽  
Vehicle Simulation ◽  
Yaw Rate ◽  
Wheel Turning ◽  
Double Phase ◽  
All Wheel Steering

In order to improve low-speed flexibility and high-speed handling and stability of multi-axle vehicle, a double-phase steering system was designed with planetary gear system. An in-phase steering mode is used when steering wheel turning in small angle. A adverse-phase steering mode is used when steering wheel turning in large angle. A five-axle vehicle simulation model was established with software ADAMS/VIEW. The research of all-wheel steering and non-all-wheel steering for high speed and low speed was respectively processed. When running in high speed, the lateral acceleration and yaw rate of the centroid are significantly lower when rear wheels steering in in-phase mode than the rear wheels not turning, which makes the possibility of roll and drift decrease, when vehicle overtaking in high-speed. When running in low speed, compared with rear wheels not steering, when rear wheels sreering, lateral acceleration increased by only 12.8%, yaw rate is 17.3% higher, diameter of the centroid trajectory is reduced by 12.9%, which greatly increases the mobility and flexibility of the multi-axle vehicle when turning at low speed.

Design of Traditional Hydraulic Steering System with Variable Power

2014 ◽  
Vol 644-650 ◽  
pp. 755-758
Author(s):  
Jie Li ◽  
Jian Tong Song ◽  
Li Hong Wang ◽  
Jv Biao Yao
Keyword(s):  
High Speed ◽  
Steering System ◽  
Vehicle Speed ◽  
Hydraulic Power ◽  
Power Steering System ◽  
Power Characteristics ◽  
Power Steering ◽  
Hydraulic Steering ◽  
Hydraulic Power Steering System ◽  
Hydraulic Power Steering

Conventional hydraulic steering system has the problems of "low-speed heavy, high-speed flight" and energy-wasting when steering, the main reason is after the system is designed, the power characteristics are fixed. To solve this problem it is necessary to achieve the power characteristics of changing power steering system according to speed of vehicles, in order to offer the power that matches the speed. Using vehicle speed sensor signal to control pilot solenoid unloading valve to regulate the pressure of hydraulic system, can achieve the regulation of power characteristics, this article is based on such idea to design variable hydraulic power steering system for hydraulic power steering system of light trucks.

Stability of Controlled Road Vehicles: A Preliminary Fundamental Study

2015 ◽  
Author(s):  
Fabio della Rossa ◽  
Massimiliano Gobbi ◽  
Giampiero Mastinu ◽  
Carlo Piccardi ◽  
Giorgio Previati
Keyword(s):  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Preliminary Investigation ◽  
Basin Of Attraction ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Vehicle Speed ◽  
Vehicle Model ◽  
The Stability ◽  
Positive Effect

A comparison of the lateral stability behaviour between an autonomous vehicle, a vehicle with driver and a vehicle without driver (fixed steering wheel) is made by introducing a simple mathematical model of a vehicle running on even road. The mechanical model of the vehicle has two degrees of freedom and the related equations of motion contain the nonlinear tyre characteristics. The driver is described by a well-known model proposed in the literature. The autonomous vehicle has a virtual driver (robot) that behaves substantially like a human, but with its proper reaction time and gain. The road vehicle model has been validated. The study of vehicle stability has to be based on bifurcation analysis and a preliminary investigation is proposed here. The accurate computation of steady-state equilibria is crucial to study the stability of the three kinds of vehicles here compared. The stability of the bare vehicle without driver (fixed steering wheel) is studied in a rather complete way referring to a number of combinations of tyre characteristics. The (known) conclusion is that the understeering vehicle is stable at each lateral acceleration level and at each vehicle speed. The additional (partially unknown) conclusion is that the vehicle (model) with degradated tyres may exhibit a huge number of different bifurcations. The driver has many effects on the stability of the vehicle. One positive effect is to eliminate the many possible different equilibria of the bare vehicle and keep active one single equilibrium only. Another positive effect is to broaden the basin of attraction of stable equilibria (at least at relatively low speed). A negative effect is that, even for straight running, the driver seem introducing a subcritical Hopf bifurcation which limits the maximum forward speed of some understeering vehicles (that could run faster with fixed steering wheel). Both the mentioned positive and negative effects appear to be applicable to autonomous vehicles as well. Further studies could be useful to overcome the limitations on the stability of current autonomous vehicles that have been identified in the present research.

Training Effectiveness: How Does Driving Simulator Fidelity Influence Driver Performance?

2005 ◽  
Vol 49 (25) ◽  
pp. 2201-2205 ◽  
Author(s):  
George D. Park ◽  
R. Wade Allen ◽  
Theodore J. Rosenthal ◽  
Dary Fiorentino
Keyword(s):  
Graduation Rates ◽  
Analysis Of Variance ◽  
Performance Measures ◽  
Training Trial ◽  
Driving Simulator ◽  
Steering Wheel ◽  
Vehicle Speed ◽  
Driver Training ◽  
Driver Performance ◽  
The Difference

Driver performance effects were compared between two configuration types: 1) a low-cost, three-monitor, 135 degree field-of-view (FOV), PC desktop with PC gaming steering wheel controls and 2) a medium-cost, fixed-based, projected image, 135 degree FOV, instrumented vehicle cab. The experiment was part of a larger novice driver training experiment with teenage drivers who had yet to receive their license to drive (Allen, Park, et al. 2003). Participants drove a minimum of six training trial runs on either the three-monitor configuration (N = 180) or the vehicle cab configuration (N = 143). A 2 times 6 (configuration type x training trial runs) analysis of variance was performed for a variety of performance measures as well as a one-way analysis of variance to assess the graduation rates between the two configurations. Significant differences were found for certain performance measures suggesting that handling behaviors (i.e. braking and steering) were largely affected by the difference in controls while lane position, vehicle speed, time-to-collision, and simulator sickness ratings were largely affected by the difference in graphical display. However, non-significant differences in certain performance measures (e.g. total accidents and graduation rates) suggested that the three-monitor configuration may be as useful of a tool for driver training, assessment, and research as a higher fidelity vehicle cab.

Ranking Tires for Heavy Truck Steering Feel Performance Using a Simulation Model2

2006 ◽  
Vol 34 (1) ◽  
pp. 64-82 ◽  
Author(s):  
S. L. Haas
Keyword(s):  
Vehicle Dynamics ◽  
Performance Metrics ◽  
Steering System ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Dynamics Model ◽  
Objective Testing ◽  
Steering Feel ◽  
Wheel Torque ◽  
Heavy Truck

Abstract The effects of seven different tire sets on heavy truck steering feel characteristics were demonstrated from objective testing. Also, the steering behavior and vehicle dynamics were modeled in order to determine how well the resulting simulations could rank the steering performance of the tire sets relative to the objective results. The objective testing was performed using a 6×4 tractor with a two-axle flatbed semi-trailer. Measured data included steering wheel torque, steering wheel angle, and lateral acceleration behavior resulting from on-center-type steering tests. In addition, the hydraulic pressure from the power steering system was also measured. The tests consisted of multiple cycles at 0.2 Hz and ±0.2 g. Steering-related performance metrics were selected and calculated based on the interaction between measured parameters. The same test procedure was also applied using an analytical model of a steering system. The input was steering wheel torque, and outputs included the road wheel angles at the steer axle, which were then fed into a commercial vehicle dynamics model providing the vehicle dynamics behavior along with feedback required for the steering model (e.g., king pin moments). Tire loads and slip angles were also provided by the vehicle dynamics model and used as input to a tire model predicting tire force and moment behavior. The related metrics were subsequently computed and compared to the measured results. Effects of the different tire sets on steering characteristics were seen from both the objective and simulation tests. Seven performance metrics were applied in a ranking comparison between measured and modeled results. Correlation of the modeled to measured metrics ranged from R2 values of 0.40 to 0.99 for the seven metrics considered.

scholarly journals The experimental study on the performances of the thermoelectric generator unit affected by heat rate of exhaust system

2021 ◽  
Vol 3 (SI2) ◽  
pp. SI24-SI36
Author(s):  
THONG DUC HONG ◽  
QUAN PHAN THIEN NGHIEM ◽  
TINH VAN MAI
Keyword(s):  
Heat Loss ◽  
Output Power ◽  
High Speed ◽  
Thermoelectric Generator ◽  
Exhaust System ◽  
Heat Rate ◽  
Vehicle Speed ◽  
Insulation Material ◽  
Generator Unit ◽  
The Difference

This study examines the effect of heat rate transferring from the exhaust system of motorcycle to the environment on the performance of the Thermoelectric Generator Unit (TGU). This heat rate is changed by attaching thermal insulation material on the outside of the exhaust system and changing the heat absorbing area of the TGU. The TGU consists of 8 thermoelectric generator modules and collects heat energy from the exhaust to produce electricity. It is attached on the custom muffler of the Suzuki Sapphire 125 and tested in the speed range from 20km/h to 50km/h. The results show that this heat rate affects both the temperature and output power generated by the TGU. The reduction of this heat rate reduces the cool side temperature by limiting the warming effect of cooling air and raise the hot side temperature of the TGU by decreasing heat loss. These two effects lead to the increase of the temperature difference between both sides of the TGU and therefore the output power increases. The difference in output power between test cases can reach up to 54%. Moreover, the heat loss at exhaust tube affects both temperature and output power of TGU from low to mid vehicle speed. However, at high speed, this heat loss at the exhaust tube does not considerably affect the output power of the TGU. To summarize, by reducing the heat rate between exhaust system and environment, the TGU can reach its stable working condition faster and produces more output power. Nonetheless, reducing this heat rate too much may lead to the excess of the hot side temperature of TGU, therefore damaging the thermoelectric generator modules and reducing the conversion efficiency of the TGU.

Nonlinear Modeling and Experimental Validation of Tire Nonuniformity Induced Tangential Steering Wheel Vibrations

2006 ◽  
Author(s):  
Virgile Ayglon ◽  
Nader Jalili ◽  
Imtiaz Haque
Keyword(s):  
Degrees Of Freedom ◽  
Nonlinear Modeling ◽  
Equations Of Motion ◽  
Quantitative Measure ◽  
Steering System ◽  
Steering Wheel ◽  
Vehicle Speed ◽  
Pinion Gear ◽  
Stiffness And Damping ◽  
Vehicle Chassis

This paper describes the model integration and validation that followed the development of nonlinear models of a tire with non-uniformities, a double wishbone suspension and rack-and-pinion power steering. These submodels are integrated to investigate the effects of variation of tire, suspension and steering parameters on the transmission of tire forces acting on the wheel spindle to the steering system and vehicle chassis. The tire model is based on a rigid ring model which includes mass imbalance and balancing mass. The suspension is idealized as rigid links with seven degrees-of-freedom and the bushings are represented by spring-damper elements. The equations of motion are derived using the Lagrange multiplier method in Maple, and solved numerically using Matlab DAE solver. The steering system is idealized as a four degree-of-freedom system and considers motion of the rack, rack housing, pinion gear and steering wheel. Nonlinear compliant friction is considered between the pinion gear / rack, and the steering column / chassis interfaces. The analytical model is used to develop a quantitative measure of the relative importance of the parameters such as mass/inertia, suspension bushing stiffness and damping, torsion bar stiffness and damping, rack friction and damping, to the force transmissibility to the vehicle chassis and the steering system. Experimental results include a modal analysis, a shop-testing and road testing, which are used to cross verify the numerical simulations. The testing shows the variation of forces in the steering system due to tire imbalances, emphasizing the nonlinear variation of the nibble phenomenon with vehicle speed and tire imbalance. Results obtained from simulation matches well with the experimental measurements.

scholarly journals Angle Sensor Module for Vehicle Steering Device Based on Multi-Track Impulse Ring

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 526 ◽  
Author(s):  
Seong Woo ◽  
Young Park ◽  
Ju Lee ◽  
Chun Han ◽  
Sungdae Na ◽  
...  
Keyword(s):  
Signal Processing ◽  
Electromagnetic Interference ◽  
High Speed ◽  
Electronic Control Unit ◽  
Steering System ◽  
Steering Wheel ◽  
Module Structure ◽  
Angle Sensor ◽  
Technical Requirements ◽  
Sensor Module

In step with the development of Industry 4.0, research on automatic operation technology and components related to automobiles is continuously being conducted. In particular, the torque angle sensor (TAS) module of the steering wheel system is considered to be a core technology owing to its precise angle, torque sensing, and high-speed signal processing. In the case of conventional TAS modules, in addition to the complicated gear structure, there is an error in angle detection due to the backlash between the main and sub-gear. In this paper, we propose a multi-track encoder-based vehicle steering system, which is incorporated with a TAS module structure that minimizes the number of components and the angle detection error of the module compared with existing TAS modules. We also fabricated and tested an angle detection signal processing board and evaluated it on a test stand. As a result, we could confirm its excellent performance of an average deviation of 0.4° and applicability to actual vehicles by evaluating its electromagnetic interference (EMI) environmental reliability. The ultimate goal of the TAS module is to detect the target steering angle with minimal computation by the steering or main electronic control unit (ECU) to meet the needs of the rapidly growing vehicle technology. The verified angle detection module can be applied to an actual steering system in accordance with the mentioned technical requirements.

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