scholarly journals Snow-covered obstacles’ effect on vehicle mobility

2020 ◽  
Author(s):  
Mark Bodie ◽  
Michael Parker ◽  
Alexander Stott ◽  
Bruce Elder
Keyword(s):  
Path Planning ◽  
Snow Cover ◽  
Normal Force ◽  
High Mobility ◽  
Vehicle Body ◽  
Unmanned Aerial Systems ◽  
Body Acceleration ◽  
Vehicle Response ◽  
Quarter Car ◽  
Vehicle Test

The Mobility in Complex Environments project used unmanned aerial systems (UAS) to identify obstacles and to provide path planning in forward operational locations. The UAS were equipped with remote-sensing devices, such as photogrammetry and lidar, to identify obstacles. The path-planning algorithms incorporated the detected obstacles to then identify the fastest and safest vehicle routes. Future algorithms should incorporate vehicle characteristics as each type of vehicle will perform differently over a given obstacle, resulting in distinctive optimal paths. This study explored the effect of snow-covered obstacles on dynamic vehicle response. Vehicle tests used an instrumented HMMWV (high mobility multipurpose wheeled vehicle) driven over obstacles with and without snow cover. Tests showed a 45% reduction in normal force variation and a 43% reduction in body acceleration associated with a 14.5 cm snow cover. To predict vehicle body acceleration and normal force response, we developed two quarter-car models: rigid terrain and deformable snow terrain quarter-car models. The simple quarter models provided reasonable agreement with the vehicle test data. We also used the models to analyze the effects of vehicle parameters, such as ground pressure, to understand the effect of snow cover on vehicle response.

UAS Mission Path Planning System (MPPS) Using Hybrid-Game Coupled to Multi-Objective Optimiser

2009 ◽  
Author(s):  
DongSeop Lee ◽  
Jacques Periaux ◽  
Luis Felipe Gonzalez
Keyword(s):  
Path Planning ◽  
Computational Cost ◽  
Optimization Techniques ◽  
Planning System ◽  
Unmanned Aerial Systems ◽  
Three Dimension ◽  
Design Quality ◽  
Nsga Ii ◽  
Start Position ◽  
Multi Objective

This paper presents the application of advanced optimization techniques to Unmanned Aerial Systems (UAS) Mission Path Planning System (MPPS) using Multi-Objective Evolutionary Algorithms (MOEAs). Two types of multi-objective optimizers are compared; the MOEA Non-dominated Sorting Genetic Algorithms II (NSGA-II) and a Hybrid Game strategy are implemented to produce a set of optimal collision-free trajectories in three-dimensional environment. The resulting trajectories on a three-dimension terrain are collision-free and are represented by using Be´zier spline curves from start position to target and then target to start position or different position with altitude constraints. The efficiency of the two optimization methods is compared in terms of computational cost and design quality. Numerical results show the benefits of adding a Hybrid-Game strategy to a MOEA and for a MPPS.

Golden Section Search Based Optimization of Road Vehicle Suspension System

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Prasad Bali ◽  
C.V. Chandrashekara
Keyword(s):  
Ride Comfort ◽  
Golden Section ◽  
Optimization Technique ◽  
Relative Displacement ◽  
Suspension System ◽  
Vehicle Body ◽  
Vehicle Handling ◽  
Golden Section Search ◽  
Design Requirements ◽  
Quarter Car

Suspension system is an important part of a vehicle which connects the road wheels and vehicle body. The major function of suspension is to isolate vehicle body from road disturbances. The design of suspension system is generally a compromise between many design requirements that aim to provide a comfortable ride and good vehicle handling. An optimization technique is used to choose the suspension parameters that meet these design requirements. In this present work a two degree of freedom quarter car vehicle vibration model is considered for optimization. Sprung mass acceleration and relative displacement of quarter car are considered as the measure of ride comfort and vehicle handling respectively. Golden section search optimization technique is used for single objective optimization of quarter car considering sprung mass acceleration as objective function and relative displacement as constraint. It is noticed that the accuracy level in getting the optimized value using this approach is comparatively high and reliable..

scholarly journals Energy Modeling and Power Measurement for Three-Wheeled Omnidirectional Mobile Robots for Path Planning

Electronics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 843 ◽  
Author(s):  
Linfei Hou ◽  
Liang Zhang ◽  
Jongwon Kim
Keyword(s):  
Path Planning ◽  
Power Consumption ◽  
Mobile Robots ◽  
High Mobility ◽  
Intelligent Manufacturing ◽  
Power Measurement ◽  
Research Focus ◽  
Planning And Control ◽  
Perfect Symmetry ◽  
And Control

Due to their high mobility, mobile robots (MR) are widely used in intelligent manufacturing. Due to the perfect symmetry of the MR of the three-wheeled moving chassis, it can move quickly in a crowded and complex factory environment. Because it is powered by a lithium battery, in order to improve its energy efficiency, we need to ensure that its power consumption is reduced as much as possible in order to avoid frequent battery replacement. The power consumption of MRs has also become an important research focus for researchers. Therefore, a power consumption modeling of the omnidirectional mobility of the three-wheeled omnidirectional mobile robot (TOMR) is proposed in this paper. When TOMR advances heading at different angles, the speed of each wheel changes dramatically. So, the power consumption of robots will also be greatly changed. In this paper, the energy and power consumption of the robot heading in different directions is analyzed and modeled by formulas. This research can be valuable for path planning and control design.

The Influence of Tire Damping in Quarter Car Active Suspension Models

1991 ◽  
Vol 113 (1) ◽  
pp. 134-137 ◽  
Author(s):  
J. A. Levitt ◽  
N. G. Zorka
Keyword(s):  
Damping Ratio ◽  
Active Suspension ◽  
Vertical Acceleration ◽  
Body Acceleration ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Quarter Car ◽  
Control Forces ◽  
And Control ◽  
Suspension Models

Setting tire damping to zero when modeling automotive active suspension systems compels the misleading conclusions that, at the wheelhop frequency, no matter what forces are exerted between sprung and unsprung masses, their motion are uncoupled, and the vertical acceleration of the sprung mass will be unaffected. Alternatively, taking tire damping to be small but nonzero, the motions of the sprung and unsprung masses are coupled at all frequencies, and control forces can be used to reduce the sprung mass vertical acceleration at the wheelhop frequency. The effect of introducing tire damping can be quite large. In the case of a force law chosen to enhance ride along a straight smooth road, where road holding is not a major concern, setting the tire damping ratio to 0.02 reduces rms body acceleration by 30 percent.

Design and comparisons of adaptive harmonic control for a quarter-car active suspension

2021 ◽  
pp. 095440702110192
Author(s):  
Teodor-Constantin Nichiţelea ◽  
Maria-Geanina Unguritu
Keyword(s):  
Active Suspension ◽  
The Body ◽  
Control Algorithms ◽  
Multiple Control ◽  
Control Solution ◽  
Body Acceleration ◽  
Front Suspension ◽  
The Road ◽  
Harmonic Control ◽  
Quarter Car

Car suspensions have the job to keep the tires in contact with the road surface as much as possible, to deliver steering stability with good handling and to guarantee passenger comfort. Most modern vehicles have independent front suspension and many vehicles also have independent rear suspension. Independent suspensions are preferred instead of dependent suspensions for their better ride handling, stability, steering and comfort but they provide less overall strength and a complex design which increases the cost and maintenance expenses for such a suspension. For this reason, automotive engineers struggle to discover new suspension components or advanced control solutions. Taking a step forward in this direction, the paper presents in the beginning one of the well-known mathematical models of a quarter-car active suspension. The obtained model is then implemented in a MATLAB/Simulink simulation which compares multiple control solutions. The only feedback considered for each control algorithm is the measurement of the body acceleration. Among these investigated control algorithms is the adaptive harmonic control solution proposed by this paper. The controller generates a harmonic control signal with variable amplitude and frequency based on the body acceleration feedback. The comparison analysis shows that the proposed control solution demonstrates quite good potential, generating in some cases better results than the other control algorithms.

Fuzzy Control of Vehicle Suspension System

2011 ◽  
Vol 383-390 ◽  
pp. 2012-2017 ◽  
Author(s):  
Guo Quan Yang ◽  
You Qun Zhao
Keyword(s):  
Fuzzy Control ◽  
Ride Comfort ◽  
Fuzzy Controller ◽  
Suspension System ◽  
The Body ◽  
Vehicle Body ◽  
Vehicle Suspension ◽  
Body Acceleration ◽  
Vehicle Suspension System ◽  
Fuzzy Logic Technique

In this paper, a semi-active suspension system has been proposed to improve the ride comfort, and a 2 DOF vehicle system is designed to simulate the actions of vehicle suspension system. The purpose of a suspension system is to support the vehicle body and increase ride comfort. The aim of the work described in the paper was to illustrate the application of fuzzy logic technique to the control of a continuously damping automotive suspension system. The ride comfort is improved by means of the reduction of the body acceleration caused by the car body when road disturbances from smooth road and real road roughness. Based on MATLAB fuzzy control toolbox, fuzzy controller is designed. Simulation analysis of suspension system is preceded by using MATLAB/Simulink7.0. The result shows that this control can improve the body acceleration, suspension distortion etc.

Design and Path Planning for a Spherical Rolling Robot

2013 ◽  
Author(s):  
Jaeyeon Lee ◽  
Wooram Park
Keyword(s):  
Path Planning ◽  
Deterministic Model ◽  
High Mobility ◽  
Planning Method ◽  
Probability Method ◽  
Spherical Robot ◽  
Stochastic Behavior ◽  
Starting Location ◽  
Probable Path ◽  
Rolling Robot

Several designs for a spherical rolling robot have been suggested and some of them were implemented. The kinematics and dynamics study as well as the path planning for the rolling robot are based on the assumption that the deterministic model describes the actual rolling robot successfully. However, due to the high mobility of the sphere, the stochastic behavior is obviously observed. In this paper, we first build a rolling robot to confirm the stochasticity. The robot is actuated by a mass-shifting mechanism where an unbalanced weight inside the spherical robot is rotated by two motors, and the imbalance induced by the weight makes the robot roll. After confirming that this actual rolling robot shows the stochastic behavior, we propose a path planning method for the spherical robot rolling on the plane. The path-of-probability method is applied to generate the most probable path from starting location to destination. This planning method uses the stochasticity of the system to produce the probability density function, and generates the piece-wise short steps for the robot move, which construct the whole trajectory that the robot should follow.

scholarly journals Hardware in the Loop Testing of Adaptive Inertia Weight PSO-Tuned LQR Applied to Vehicle Suspension Control

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Joshua Sunder David Reddipogu ◽  
Vinodh Kumar Elumalai
Keyword(s):  
Optimization Problem ◽  
Ride Comfort ◽  
Controller Design ◽  
Linear Quadratic Regulator ◽  
Vehicle Body ◽  
Linear Quadratic ◽  
Body Acceleration ◽  
Inertia Weight ◽  
Optimal Weights ◽  
Road Profile

This paper presents an adaptive inertia weight particle swarm optimization (AIWPSO) employed for solving the multiobjective weight optimization problem of LQR applied for the vehicle active suspension system (ASS). To meet the competing control objectives of ASS including the ride comfort, road handling, and suspension travel, the state feedback controller design for ASS is formulated as an optimization problem and an improved PSO is employed for finding the optimal weights of the linear-quadratic regulator (LQR). Specifically, for solving the premature convergence of the particles and imbalance between exploration and exploitation capabilities of PSO, an adaptive inertia weight that updates the velocity of the particles based on the success rate is used. The efficacy of the AIWPSO-tuned LQR is experimentally tested on a quarter-car ASS plant using the hardware in loop (HIL) testing for an uneven road surface. Experimental results highlight that, compared to conventional PSO-tuned LQR, the proposed scheme can significantly minimize the vehicle body acceleration due to irregular road profile while guaranteeing the minimum tire friction for passenger safety. The ISO 2361-1 standards adopted to evaluate the ride and health criteria substantiate that the proposed scheme reduces the vibration dose value by 25.34% for a bumpy road profile. Moreover, the cumulative power spectral density (CPSD) of vehicle body acceleration assessed in both low- and high-frequency regions manifests the significant improvement in the ride comfort.

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