Triangular Tracked Wheel

Amir H. Soltanzadehamirhst@gmail.com

ME Dep @ IAUCTB

A new hybrid locomotion mechanism for higher mobility

IAUCTB 2/12Mechanical Engineering Dep.

Acknowledgement

Dr. Hossein Mahbadi

Professor of Mechanical Engineering

Islamic Azad University of Central Tehran Branch

Head of ME Dep. and Robotics Lab @ IAUCTB

IAUCTB 3/12Mechanical Engineering Dep.

Outlines

Kinematics of TTW locomotion mechanism

IAUCTB 4/12Mechanical Engineering Dep.

Motivation

Developing robots to be used in USAR application

SearchTo look through in a place or in an area carefully in order to find something missing or lost

RescueTo free or deliver victim from confinement.

IAUCTB 5/12Mechanical Engineering Dep.

The Problem

Mobility Power Consumption Size Weight Robustness

Void:1’x2.5’x60’

IAUCTB 6/12Mechanical Engineering Dep.

Earlier Works

Joint Control

Space CatVan Winnendael et al, EPFL (1998)

Stair Climbing VehicleJ. Florystair, U.S. patents (1966)

Passive Active

IAUCTB 7/12Mechanical Engineering Dep.

TTW

Triangular Tracked Wheel

1. Moving tracks 2. Rotating triangular frames

2 DOF

IAUCTB 8/12Mechanical Engineering Dep.

Powertrain

4 TTW’s in a robot and 2 DOF in each TTW, does it mean 8 motors are required?

2 motors for tracks (both right, both left)2 motors for triangular frames (both front, both rear)

4 motors are needed!

IAUCTB 9/12Mechanical Engineering Dep.

Locomotion Styles

Locomotion

Continuous (85%) Discrete (5%) Combined (10%)

Discrete movement?

Active (Position controlled)/Passive Active (velocity controlled) Active (velocity controlled)

Velocity of CG periodically becomes 0 three times in a cycle and causes a “Stop-Go”

movement style .Like a Four-legged robot!

IAUCTB 10/12Mechanical Engineering Dep.

Traction Management

Joints’ Active Controlling (Position Mode)

Positive (70%) Negative (5%) Trans (10%)

Maximum traction

Tracked vehicle

Climbing slopes

Minimum traction Directional traction

Wheeled vehicle

Turning

Traversing in stones

To reduce power consumption of Joint Controlling System, Positive configuration is achieved in Passive mode.

IAUCTB 11/12Mechanical Engineering Dep.

Surface Adaptation

Joints’ Passive Controlling

Lateral Adaptation Axial Adaptation

To enhance traction without any processing load on control system

Axial Adaptation can also be performed even in Active joint controlling!

IAUCTB 12/12Mechanical Engineering Dep.

Thank You!