Session: MR-05-01 - Motion Planning, Dynamics, and Control of Robots

Paper Number: 90206

90206 - "On the Edge" Obstacle Surmounting Method Using Hybrid Locomotion 

This paper presents 'on the edge' obstacle surmounting method for QuadRunner, a hybrid quadruped robot, to overcome obstacles using hybrid locomotion where both legged and wheel configurations are utilized. When obstacle heights exceed the workspace of its leg, QuadRunner becomes quasi-statically mismatched and fails to achieve the climbing task quasi-statically. By incorporating its body as contact support, the center of gravity (COG) of QuadRunner can be successfully shifted on top of the obstacle to perform the surmounting task quasi-statically. Thanks to the unique leg design of QuadRunner, the robot can be modeled as two different kinematic chains, namely, a four-bar linkage (4R) and a slider-crank linkage (3R1P). With these mechanisms, the robot can maneuver from the initial configuration of standing on the ground plane to the desired configuration of standing on the tread. Here we detail the sub-state strategy for its surmount task, where QuadRunner goes through the sub-states LEAN, HOOK, FOUR BAR, SLIDE, and GET-UP in order to climb obstacles. In addition, obstacle range limitations of the operation are analyzed, friction and torque requirements for climbing are identified. With our proposed method, QuadRunner can surmount obstacles of heights between 10 cm and 22 cm (higher than its kinematic max height of 16 cm) within 25 seconds. Lastly, a reliability test shows that the robot can climb the obstacle with a 70% success rate.

Presenting Author: Gim Song Soh Singapore University of Technology and Design

Presenting Author Biography: NA

Authors:

ALPER YELDAN SUTD
Abhimanyu Arora Singapore University of Technology and Design
Gim Song Soh Singapore University of Technology and Design