Implementation of SSM to Lateral Guided Steering Vehicle With Body Fixed High-Speed Camera

2013 ◽  
Author(s):  
Yoshihiro Takita ◽  
Date Hisashi
Keyword(s):  
High Speed ◽  
Rear Wheel ◽  
Front Wheel ◽  
Dump Truck ◽  
Reverse Phase ◽  
Automated Vehicle ◽  
Steering Mechanism ◽  
And Performance ◽  
The Stability ◽  
Rotating Camera

This paper proposes an SSM (Sensor Steering Mechanism) for a lateral guided vehicle with an articulated body. Authors demonstrated a simple lateral guiding method SSM for front wheel steer type, the reverse phase four-wheel steer type and rear wheel steer type vehicles. SSM presents a stable lateral guiding performance for automated vehicle that following a straight and curved path created by a guideway. This paper proposes a simplified SSM to remove the following servo system for a rotating camera. The simplified SSM is applied to 1/25 scale articulated dump truck that was developed and discussed in the previous paper. The stability of the simplified SSM is discussed. Experimental and simulation results show stable movement and performance of the proposed method.

High-Speed Driving of a Lateral Guided Vehicle With Sensor Steering Mechanism

1999 ◽  
Author(s):  
Yoshihiro Takita
Keyword(s):  
Mobile Robot ◽  
Dynamic Behavior ◽  
High Speed ◽  
Simple Relation ◽  
Front Wheel ◽  
Dual Mode ◽  
Automatic Guided Vehicles ◽  
Steering Mechanism ◽  
The Stability ◽  
Moving Speed

Abstract This paper proposes a simple relation of the lateral guidance mechanism for automatic, guided vehicles and Dual Mode Trucks, and named it SSM (Sensor Steering Mechanism). SSM consists of a guide bar and deceleration gear which reduces the bar angle to one-second. In order to demonstrate the effectiveness of this relation, this paper examines the stability of the dynamic behavior of the front wheel steering of the vehicle. These results show that there is no limitation of the moving speed unless without a slip of the tire. For the test, a self-standing mobile robot, reduced to a scale of one-twentieth of the real car, is developed. Experimental results show that high-speed automatic moving is realized by using this relation.

Stability and Control of Tooling System for High-Speed Machining

2014 ◽  
Vol 684 ◽  
pp. 375-380
Author(s):  
Deng Sheng Zheng ◽  
Jian Chen ◽  
D.F. Tao ◽  
L. Lv ◽  
Gui Cheng Wang
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
System Stability ◽  
Finite Model ◽  
High Speed Machining ◽  
Cnc Machine ◽  
And Performance ◽  
The Stability ◽  
Tooling System ◽  
And Control

Tooling system for high-speed machining is one of the key components of high-end CNC machine , its stability and reliability directly affects the quality and performance of the machine. Based on the finite element method, developing a 3D finite model of high-speed machining tool system, studying on the stability of the high Speed machining tool from the natural frequency by the method of modal analysis. Analysis the amount of the overhang and clamping of the tooling , different shank taper interference fit and under different speed conditions, which affects the natural frequency of high-speed machining tool system. Proposed to the approach of improving system stability, which also provides a theoretical basis for the development of new high-speed machining tool system.

Simulation Study on Tractor’s Same-Rut-Steering Mechanism

2011 ◽  
Vol 338 ◽  
pp. 236-240
Author(s):  
Ren Cai Zhao ◽  
Xu Ma ◽  
Long Qi ◽  
Rui Chuan Li
Keyword(s):  
Soil Compaction ◽  
Three Dimensional ◽  
Rear Wheel ◽  
Front Wheel ◽  
Steering Wheel ◽  
Steering Mechanism ◽  
Environment Simulation ◽  
Parameterized Model ◽  
Simulation Results ◽  
Deflection Rate

When tractor steers in the same rut, it can not only improve its flexibility in steering, but also reduce soil compaction and crop rolling. In this paper , the concept of tractor steering in the same rut was proposed on the basis of four-wheel-steering (4WS) theory, and the angle relationship between front wheel and rear wheel, which can achieve the same-rut-steering, was established. A three dimensional parameterized model of tractor’s same-rut-steering mechanism was established by the Pro/E software, and its running tracks were simulated in the ADAMS environment. Simulation results show that the same-rut-steering accuracy was affected to some extent when tractor’s speed or steering wheel deflection rate was changed. At last, methods for improving the same-rut-steering accuracy were put forward.

Design and Performance Simulation of a Power-Integrated Transmission Mechanism

2013 ◽  
Vol 397-400 ◽  
pp. 388-392
Author(s):  
Chou Mo ◽  
Ji Qing Chen ◽  
Feng Chong Lan
Keyword(s):  
Hybrid Electric Vehicle ◽  
Rear Wheel ◽  
Front Wheel ◽  
Transmission Mechanism ◽  
System Structure ◽  
Performance Simulation ◽  
Operating Modes ◽  
Wheel Drive ◽  
And Performance ◽  
Four Wheel Drive

The power system structure of a hybrid electric vehicle (HEV) critically affects the performance of the vehicle. This study presents a power-integrated transmission mechanism that can provide six basic operating modes that can be further classified into 15 sub-modes. Switching clutch conditions helps transmission achieve speed and torque coupling. The proposed mechanism has CVT capability and an extended range capacity, and it is applicable to front-wheel-drive, rear-wheel-drive, or four-wheel-drive HEVs. A performance simulation on power and economy via Matlab and Cruise software demonstrates that the performance of the proposed transmission mechanism meets the target. Therefore, the mechanism is a feasible candidate for use in HEVs.

scholarly journals Self-Recirculating Casing Treatment Concept for Enhanced Compressor Performance

2002 ◽  
Author(s):  
Michael D. Hathaway
Keyword(s):  
High Speed ◽  
Flow Characteristics ◽  
Treatment Concept ◽  
Casing Treatment ◽  
Compressor Performance ◽  
And Performance ◽  
The Stability ◽  
The Impact ◽  
Compressor Efficiency ◽  
Transonic Rotor

A state-of-the-art CFD code (APNASA) was employed in a computationally based investigation of the impact of casing bleed and injection on the stability and performance of a moderate speed fan rotor wherein the stalling mass flow is controlled by tip flow field breakdown. The investigation was guided by observed trends in endwall flow characteristics (e.g., increasing endwall aerodynamic blockage) as stall is approached, and based on the hypothesis that application of bleed or injection can mitigate these trends. The “best” bleed and injection configurations were then combined to yield a self-recirculating casing treatment concept. The results of this investigation yielded: 1) identification of the fluid mechanisms which precipitate stall of tip critical blade rows, and 2) an approach to recirculated casing treatment which results in increased compressor stall range with minimal or no loss in efficiency. Subsequent application of this approach to a high speed transonic rotor successfully yielded significant improvements in stall range with no loss in compressor efficiency.

scholarly journals Research on the nonlinear dynamic characteristics of opposed high-speed gas bearing systems

2019 ◽  
Vol 39 (3) ◽  
pp. 502-522 ◽  
Author(s):  
Cheng-Chi Wang ◽  
Rong-Mao Lee ◽  
Chih-Jer Lin ◽  
Chih-Yung Huang ◽  
Tsui-Er Lee
Keyword(s):  
Nonlinear Dynamic ◽  
High Speed ◽  
Working Environment ◽  
Strong Nonlinearity ◽  
Mixing Method ◽  
Rotor Center ◽  
And Performance ◽  
The Stability ◽  
Gas Bearing ◽  
Bearing System

In recent years, the opposed high-speed gas bearing system has been gradually valued and used in the field of precision machinery, especially for precision instruments and mechanisms requiring high speed, high precision, and high rigidity. Although the bearing capacity is not as good as the oil film bearings, it can provide a working environment where the rotor can generate high speed and low heat without deformation of the shaft, and the gas pressure distribution of clearance in bearing also has better stability. Due to the strong nonlinearity of the gas film pressure function of gas bearings and the fact that the actual shaft system possesses dynamic problems including critical speed, spindle imbalance or improper bearing design, it will cause the rotation process of the shaft to produce a nonperiodic motion and instability, and even chaotic motion under certain parameters. And these irregular movements can even cause machine damage or process delays when serious, so in order to understand the process of working under the conditions where the system will have a nonperiodic phenomenon and to avoid the occurrence of irregular vibration especially chaos. In this paper, the opposed high-speed gas bearing system feature will be discussed in detail with three different numerical analysis methods, i.e. the finite difference method, perturbation method, and mixing method. The relevant theories include dynamic trajectories, spectrum analysis, bifurcation diagram, Poincare map, and the maximum Lyapunov exponents. From the results of nonlinear dynamic behavior of the rotor center, periodic and nonperiodic motions occur at different rotor masses and bearing parameters, respectively. Especially, for the chaos of shaft exists at specific intervals and can be distinguished efficiently. Meanwhile, it is found to ensure that the bearing system can suppress the phenomena of chaos actively by adjusting the bearing parameters, and reduce the system loss caused by irregular vibration. It is expected to be an important basis for designing a precision shaft or mechanism and to enhance the stability and performance of bearing system.

Mechanical Structural Optimization and Research for an Intelligent Vehicle Model

2013 ◽  
Vol 302 ◽  
pp. 486-489
Author(s):  
Chong Jie Leng ◽  
Hui Yu Xiang ◽  
Xiao Zhuang Zhou ◽  
Jia Jun Huang
Keyword(s):  
College Students ◽  
Structural Optimization ◽  
Rear Wheel ◽  
Front Wheel ◽  
Intelligent Vehicle ◽  
Main Study ◽  
Vehicle Model ◽  
Steering Mechanism ◽  
Wheel Alignment ◽  
Control Procedures

This paper utilized an intelligent vehicle model for the “Freescale” Cup National College Students' Intelligent Vehicle competition as the main study object. Under the prerequisite of adopting the same control procedures and algorithms, the mechanical structures and its parameters of the model vehicle which influence the running performance, such as front wheel alignment, steering mechanism and rear wheel deceleration mechanism are optimally designed and adjusted .It has been proved that the scheme induced the model vehicle driving fast and stable on the path-complex track and thus to achieve reasonable effects.

A Multibody Motorcycle Model for the Analysis and Prediction of Chatter Vibrations

2013 ◽  
Author(s):  
Giuseppe Catania ◽  
Luca Leonelli ◽  
Nicolò Mancinelli
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Rear Wheel ◽  
Front Wheel ◽  
Critical Discussion ◽  
Chatter Vibrations ◽  
Race Track ◽  
Chain Transmission ◽  
Linearized System ◽  
Overall Performance

The chatter phenomenon, appearing during high speed cornering maneuvers performed by racing motorcycles, consists of a self-excited vertical oscillation of both the front and rear unsprung masses in the range of frequency between 17 and 22 Hz. The suspensions are not generally able to dampen the above vibrations which start from the rear wheel and suddenly propagate to the front wheel during the corner entry phase, making the vehicle’s handling unpredictable and, ultimately, weakening the overall performance, that is the lap time. It is not clear which is the determining factor causing this phenomenon. Therefore, numerical simulation on a three dimensional, multibody motorcycle model is proposed, taking into account the effects of the major parameters involved, in order to highlight which of them takes part in the vibration. Accurate models for tire and drivetrain have been developed, making it possible to consider tire carcass deformability, chain transmission in both traction and braking states, full drivetrain inertia and anti-hop clutch effect. A critical maneuver experimentally measured on the race track is analyzed. The modal response of the linearized system is evaluated for several configurations extracted from the maneuver. The above maneuver is then simulated with the model, showing the actual vibration uprising. A critical discussion of the possible physical interpretations of the phenomenon is given.

Rear Wheel Steering Dynamics Compared to Front Steering

1990 ◽  
Vol 112 (1) ◽  
pp. 88-93 ◽  
Author(s):  
J. C. Whitehead
Keyword(s):  
High Speed ◽  
Rear Wheel ◽  
Front Wheel ◽  
Slip Angle ◽  
Vehicle Speed ◽  
Lateral Dynamics ◽  
High Speeds ◽  
Control Response ◽  
Steady State Responses ◽  
State Responses

The lateral dynamics of rear wheel steering vehicles are examined using low order linear mathematical models. The response to rear steer angle inputs differs significantly from the front wheel steering response at low speeds. However, both the transient and steady state responses become less dependent on which wheels are steered as vehicle speed increases. This fact indicates that the unusual fixed control response does not alone cause rear wheel steering vehicles to be unsafe at high speeds. The free control instability unique to rear wheel steering vehicles is analyzed using a torque input model which treats steer angle as a degree of freedom. The cause of this unstable weave mode and the stable front wheel steering weave mode is a ratio of tire slip angle to steer angle in excess of unity during high speed cornering.

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