Virtual Model Control of a Hexapod Walking Robot

Item

Title
en_US Virtual Model Control of a Hexapod Walking Robot
Creator
en_US Torres, Ann L.
Date
2004-10-20T20:29:15Z
Date Available
2004-10-20T20:29:15Z
Date Issued
en_US 1996-12-01
Identifier
en_US AITR-1582
uri
http://hdl.handle.net/1721.1/7083
Abstract
en_US Since robots are typically designed with an individual actuator at each joint, the control of these systems is often difficult and non-intuitive. This thesis explains a more intuitive control scheme called Virtual Model Control. This thesis also demonstrates the simplicity and ease of this control method by using it to control a simulated walking hexapod. Virtual Model Control uses imagined mechanical components to create virtual forces, which are applied through the joint torques of real actuators. This method produces a straightforward means of controlling joint torques to produce a desired robot behavior. Due to the intuitive nature of this control scheme, the design of a virtual model controller is similar to the design of a controller with basic mechanical components. The ease of this control scheme facilitates the use of a high level control system which can be used above the low level virtual model controllers to modulate the parameters of the imaginary mechanical components. In order to apply Virtual Model Control to parallel mechanisms, a solution to the force distribution problem is required. This thesis uses an extension of Gardner`s Partitioned Force Control method which allows for the specification of constrained degrees of freedom. This virtual model control technique was applied to a simulated hexapod robot. Although the hexapod is a highly non-linear, parallel mechanism, the virtual models allowed text-book control solutions to be used while the robot was walking. Using a simple linear control law, the robot walked while simultaneously balancing a pendulum and tracking an object.
Extent
2023158 bytes
2555298 bytes
Format
application/postscript
application/pdf
Language
en_US
Relation
en_US AITR-1582
Item sets
AI Technical Reports (1964 - 2004)