Accession Number:

ADA543230

Title:

Minimalistic Dynamic Climbing

Descriptive Note:

Doctoral thesis

Corporate Author:

CARNEGIE-MELLON UNIV PITTSBURGH PA ROBOTICS INST

Personal Author(s):

Report Date:

2010-11-01

Pagination or Media Count:

201.0

Abstract:

Dynamics in locomotion is highly useful, as can be seen in animals. Although dynamic maneuvers are beneficial, only a few engineered systems use them as the design and control are often extremely complicated. This thesis explores a family of dynamic climbing robots which extend robotic dynamic legged locomotion from horizontal motions such as walking and running, to vertical motions such as leaping. Motion of these dynamic robots resembles the motion of an athlete jumping and climbing inside a chute. The mechanisms described achieve dynamic, vertical motions while retaining simplicity in design and control. The first mechanism called DSAC, for Dynamic Single Actuated Climber, comprises only two links connected by a single oscillating actuator. This simple, open-loop oscillation, propels the robot stably between two vertical walls. By rotating the axis of revolution of the single actuator by 90 degrees, we also developed a simpler robot that can be easily miniaturized and can be used to climb inside tubes. The DTAR, for Dynamic Tube Ascending Robot, uses a single continuously rotating motor, unlike the oscillating DSAC motor. This continuous rotation even further simplifies and enables the miniaturization. The last mechanism explored is the ParkourBot which sacrifices some simplicity shown in the first two mechanism in favor of efficiency and more versatile climbing. This mechanism comprises two efficient springy legs connected to a body. We use this family of dynamic climbers to explore a minimalist approach to locomotion. We first analyze open-loop stability characteristics. We show an open-loop, sensorless control, such as fixed oscillation of the DSACs leg can converge to a stable orbit. We show change in the mechanisms parameters not only changes the stability, but also changes the climbing pattern from a symmetric climb to a limping, non-symmetric climb. We show open-loop behavior can be used to traverse more complex terrains by incrementally adding feedback.

Subject Categories:

  • Theoretical Mathematics
  • Cybernetics
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE