scholarly journals Slip Ratio Based Traction Coordinating Control of Wheeled Lunar Rover with Rocker Bogie

2011 ◽  
Vol 15 ◽  
pp. 510-515 ◽  
Author(s):  
Shumei Wu ◽  
Linhui Li ◽  
Yibing Zhao ◽  
Ming Li
Keyword(s):  
Slip Ratio ◽  
Lunar Rover ◽  
Coordinating Control

Development of Quality Measurement System Using Slip Ratio Model with Homogenization System

2019 ◽  
Vol 18 (0) ◽  
pp. 109-118
Author(s):  
Kazuma MINOTE ◽  
Yuki SAKAMOTO ◽  
Shohei TANE ◽  
Yo NAKAJIMA ◽  
Atsuhiro FURUICHI ◽  
...  
Keyword(s):  
Measurement System ◽  
Quality Measurement ◽  
Ratio Model ◽  
Slip Ratio

Normalization of Tire Force and Moment Data

1993 ◽  
Vol 21 (2) ◽  
pp. 91-119 ◽  
Author(s):  
H. S. Radt ◽  
D. A. Glemming
Keyword(s):  
Surface Water ◽  
Lateral Force ◽  
Slip Angle ◽  
Inflation Pressure ◽  
Slip Ratio ◽  
Tire Force ◽  
Camber Angle ◽  
Potential Benefits ◽  
Overturning Moment ◽  
Semi Empirical

Abstract Semi-empirical theories of tire mechanics are employed to determine appropriate means to normalize forces, moments, angles, and slip ratios. Force and moment measurements on a P195/70R 14 tire were normalized to show that data at different loads could then be superimposed, yielding close to one normalized curve. Included are lateral force, self-aligning torque, and overturning moment as a function of slip angle, inclination angle, slip ratio, and combinations. It is shown that, by proper normalization of the data, one need only determine one normalized force function that applies to combinations of slip angle, camber angle, and load or slip angle, slip ratio, and load. Normalized curves are compared for the effects of inflation pressure and surface water thickness. Potential benefits as well as limitations and deficiencies of the approach are presented.

An Implicit to Explicit FEA Solving of Tire F&M with Detailed Tread Blocks

2012 ◽  
Vol 40 (2) ◽  
pp. 83-107 ◽  
Author(s):  
Zhao Li ◽  
Ziran R. Li ◽  
Yuanming M. Xia
Keyword(s):  
Test System ◽  
Mapping Method ◽  
Friction Model ◽  
Experimental Results ◽  
Slip Angle ◽  
Slip Ratio ◽  
The Road ◽  
Numerical Noise ◽  
Nonlinear Stress ◽  
Solving Strategy

ABSTRACT A detailed tire-rolling model (185/75R14), using the implicit to explicit FEA solving strategy, was constructed to provide a reliable, dynamic simulation with several modeling features, including mesh, material modeling, and a solving strategy that could contribute to the consideration of the serious numerical noises. High-quality hexahedral meshes of tread blocks were obtained with a combined mapping method. The actual rubber distributing and nonlinear, stress-strain relationship of the rubber and bilinear elastic reinforcement were modeled for realism. In addition, a tread-rubber friction model obtained from the Laboratory Abrasion and Skid Tester (LAT 100) was applied to simulate the interaction of the tire with the road. The force and moment (F&) behaviors of tire cornering when subjected to a slip-angle sweep of −10 to 10° were studied with that model. To demonstrate the efficiency of the proposed simulation, the computed F&M were compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering F&M agreed well with the experimental results, so the footprint shape and contact pressure distribution of several cornering conditions were investigated. Furthermore, the longitudinal forces in response to braking/driving torque application in a slip-ratio range of −100% to 100% were computed. The proposed FEA solution confines the numerical noise within a smaller range and can serve as a valid tool in tire design.

Recent Studies of Tire Braking Performance

1973 ◽  
Vol 1 (2) ◽  
pp. 121-137 ◽  
Author(s):  
J. L. McCarty ◽  
T. J. W. Leland
Keyword(s):  
Steady State ◽  
Rapid Cycling ◽  
Single Cycle ◽  
Steering Angle ◽  
Slip Ratio ◽  
Factors Affecting ◽  
Braking Performance ◽  
Constant Rate

Abstract The results from recent studies of some factors affecting tire braking and cornering performance are presented together with a discussion of the possible application of these results to the design of aircraft braking systems. The first part of the paper is concerned with steady-state braking, that is, results from tests conducted at a constant slip ratio or steering angle or both. The second part deals with cyclic braking tests, both single cycle, where brakes are applied at a constant rate until wheel lockup is achieved, and rapid cycling of the brakes under control of a currently operational antiskid system.

Lunar Rover Wheel-Terrain Interaction Model for Climbing-up-Slope Based on Terramechanics

ROBOT ◽  
2010 ◽  
Vol 32 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Zhen JIAO ◽  
Haibo GAO ◽  
Zongquan DENG ◽  
Liang DING
Keyword(s):  
Interaction Model ◽  
Lunar Rover

The role of terrain modeling in lunar rover simulation

SIMULATION ◽  
1993 ◽  
Vol 61 (1) ◽  
pp. 60-68
Author(s):  
Niranjan S. Rao ◽  
Matthew H. Appleby
Keyword(s):  
Terrain Modeling ◽  
Lunar Rover

scholarly journals Learning-Based End-to-End Path Planning for Lunar Rovers with Safety Constraints

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 796
Author(s):  
Xiaoqiang Yu ◽  
Ping Wang ◽  
Zexu Zhang
Keyword(s):  
Path Planning ◽  
Lunar Surface ◽  
Training Environment ◽  
Lunar Rover ◽  
Reward Function ◽  
Safety Constraints ◽  
Planning Algorithm ◽  
Lunar Rovers ◽  
End To End ◽  
Path Planning Algorithm

Path planning is an essential technology for lunar rover to achieve safe and efficient autonomous exploration mission, this paper proposes a learning-based end-to-end path planning algorithm for lunar rovers with safety constraints. Firstly, a training environment integrating real lunar surface terrain data was built using the Gazebo simulation environment and a lunar rover simulator was created in it to simulate the real lunar surface environment and the lunar rover system. Then an end-to-end path planning algorithm based on deep reinforcement learning method is designed, including state space, action space, network structure, reward function considering slip behavior, and training method based on proximal policy optimization. In addition, to improve the generalization ability to different lunar surface topography and different scale environments, a variety of training scenarios were set up to train the network model using the idea of curriculum learning. The simulation results show that the proposed planning algorithm can successfully achieve the end-to-end path planning of the lunar rover, and the path generated by the proposed algorithm has a higher safety guarantee compared with the classical path planning algorithm.

Sign in / Sign up

Export Citation Format

Share Document