The Effect of Transmission Design on Force-Controlled Manipulator Performance.
Abstract
The concept of manipulator force control and a corresponding emphasis on the choice of appropriate servo implementation have been developing for many years. However, the selection of appropriate mechanical hardware may ultimately be the limiting performance factor in force control. Mechanism properties, such as contact compliance, actuator-to-joint compliance, torque ripple, and highly nonlinear dry friction, affect, and often degrade, manipulator performance in force-controlled systems. This thesis describes a set of requisites for good performance, analyzes the effects of transmission-mechanism properties on force-controlled manipulators, and recommends mechanical-design strategies to improve performance. While much of the analysis applies to a broad class of transmissions, a special control-volume analysis quantities a limit on the power efficiency of tension-element drives. A single-degree-of-freedom transmission testbed was constructed and used to confirm the predicted effect of Coulomb friction on robustness; design of a cable-driven, four-degree-of-freedom, whole-arm manipulator illustrates the recommended mechanical-design strategies. (kr)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1988
- Accession Number
- ADA198131
Entities
People
- William Towsend
Organizations
- Massachusetts Institute of Technology