Have a personal or library account? Click to login
Slippage Down on Rolling Mobile Robots While Overcoming Inclined Obstacles Cover

Slippage Down on Rolling Mobile Robots While Overcoming Inclined Obstacles

Open Access
|Dec 2025

Figures & Tables

Fig. 1.

Lázaro robot
Lázaro robot

Fig. 2.

Lázaro robot showing dimensions and Xc Yc Zc frame a) Axono metric view; b) Side view
Lázaro robot showing dimensions and Xc Yc Zc frame a) Axono metric view; b) Side view

Fig. 3.

Geometric parameters used to characterize the obstacle
Geometric parameters used to characterize the obstacle

Fig. 4.

Forces at the wheel-ground contact point: a) robot wheel; b) wheel at the end effector
Forces at the wheel-ground contact point: a) robot wheel; b) wheel at the end effector

Fig. 5.

Direct angles of the maximum slope on Surface s and on the XC YC plane
Direct angles of the maximum slope on Surface s and on the XC YC plane

Fig. 6.

Results of simulations to estimate δn
Results of simulations to estimate δn

Fig. 7.

Robot overcoming obstacle with two wheels on each surface
Robot overcoming obstacle with two wheels on each surface

Fig. 8.

Robot overcoming obstacle supported by 2 wheels and the end effector
Robot overcoming obstacle supported by 2 wheels and the end effector

Fig. 9.

Simulations to validate Is with the robot touching the ground with 4 wheels
Simulations to validate Is with the robot touching the ground with 4 wheels

Fig. 10.

Results corresponding to Test "a" (Fig. 9) with F5z=0 N
Results corresponding to Test "a" (Fig. 9) with F5z=0 N

Fig. 11.

Results corresponding to Test "d" (Fig. 9) with F5z=15 N
Results corresponding to Test "d" (Fig. 9) with F5z=15 N

Fig. 12.

Results corresponding to Test "f" (Fig. 9) with F5z=45 N
Results corresponding to Test "f" (Fig. 9) with F5z=45 N

Fig. 13.

Simulations to validate Is with the robot touching the ground at three points
Simulations to validate Is with the robot touching the ground at three points

Fig. 14.

Results corresponding to Test "b" (see Fig. 13)
Results corresponding to Test "b" (see Fig. 13)

Fig. 15.

Analysis of stages for overcoming obstacles until slipping (Simulation A)
Analysis of stages for overcoming obstacles until slipping (Simulation A)

Fig. 16.

Analysis of stages for overcoming obstacles until slipping (Simulation B)
Analysis of stages for overcoming obstacles until slipping (Simulation B)

Fig. 17.

Tests conducted with the Lázaro robot to validate Is
Tests conducted with the Lázaro robot to validate Is

Fig. 18.

Results of the tests conducted with the Lázaro robot to validate Is
Results of the tests conducted with the Lázaro robot to validate Is

Geometry of obstacles and static friction coefficients used

SimulationDescriptionϕs1 (°)αs1 (°)ϕs2 (°)αs2 (°)γb1 (°)μs1μs2
AFrontal ascent-5.000.00-9.67-2.5874.941.00.2
BLateral descent7.710.007.50-4.33150.220.40.4
CLateral trench0.0010.000.0010.0025.340.40.4

Statistical analysis of simulation results to validate Is Test

TestF5 (N)Fs1Fs2μ1μ2
μ¯(N)\bar \mu ({\rm{N}})σ (N)MAPE (%)μ¯(N)\bar \mu ({\rm{N}})σ (N)MAPE (%)μ¯{\bar \mu }σMAPE (%)μ¯{\bar \mu }σMAPE (%)
a0-2.014.611.991.686.221.190.000.010.80-0.010.013.42
15-1.984.472.131.904.711.430.000.011.570.000.012.32
30-2.044.572.412.004.451.600.020.015.830.000.010.72
45-1.384.541.791.185.001.030.050.0117.250.010.050.24
b01.454.521.00-1.954.632.020.000.000.410.000.011.08
150.275.330.15-0.665.790.750.000.032.250.000.044.53
30-1.755.521.471.456.111.730.000.030.37-0.010.069.85
45-2.084.201.851.744.132.390.020.028.240.010.045.80
c0-7.547.565.167.096.317.500.000.042.27-0.020.038.75
15-8.018.755.227.216.0010.13-0.010.053.21-0.030.049.89
30-7.308.074.576.636.0913.01-0.010.056.60-0.030.059.99
d04.163.464.31-4.472.883.100.010.013.56-0.010.013.69
153.803.613.61-4.242.983.530.010.012.80-0.010.013.72
303.473.802.99-4.033.904.250.010.012.15-0.010.013.53
453.354.252.71-4.045.145.800.000.011.22-0.010.013.93
e0-9.041.776.018.611.9410.52-0.010.024.500.050.015.44
15-9.131.786.449.031.5011.73-0.010.013.820.050.018.88
30-7.577.625.887.484.079.86-0.020.0624.780.040.0115.52
45-8.152.086.778.142.5811.610.000.010.450.040.0617.69
f03.354.663.24-3.904.212.820.020.0115.82-0.020.036.28
153.996.813.49-4.486.663.950.020.0114.91-0.020.068.35
301.325.690.99-2.296.582.75-0.020.0412.12-0.020.028.81
450.775.850.53-1.715.752.76-0.020.0310.13-0.020.037.65

Statistical analysis of the simulations when the robot touches the ground at 3 points

TestFs1Fs2μ1μ2
μ¯(N)\bar \mu ({\rm{N}})σ (N)MAPE (%)μ¯(N)\bar \mu ({\rm{N}})σ (N)MAPE (%)μ¯{\bar \mu }σMAPE (%)μ¯{\bar \mu }σMAPE (%)
a0.154.100.06---0.010.040.98---
b---0.211.530.17---0.010.051.53
c-0.211.200.16---0.010.040.13---
d----0.201.230.15---0.000.040.84
e0.032.100.02---0.000.040.46---
f----0.581.840.44---0.010.051.67

Dimensional parameters of Lázaro robot

ParameterMagnitude
xf209.0 mm
xr191.0 mm
xt400.0 mm
yt398.0 mm
a1420.0 mm
d2c-282.5 mm
DOI: https://doi.org/10.2478/ama-2025-0065 | Journal eISSN: 2300-5319 | Journal ISSN: 1898-4088
Language: English
Page range: 568 - 584
Submitted on: Jan 27, 2025
Accepted on: Sep 28, 2025
Published on: Dec 19, 2025
Published by: Bialystok University of Technology
In partnership with: Paradigm Publishing Services
Publication frequency: 4 issues per year

© 2025 Jesús M. GARCÍA, Franklyn G. DUARTE, published by Bialystok University of Technology
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.