US 5,946,449 A · Precision apparatus with non-rigid, imprecise structure, and method for operating same

Abstract

An apparatus which allows one to maintain precision placement of a manipulator which undergoes repeated controlled motions or trajectories is provided. The structure of the apparatus is compliant such that the manipulator may be displaced by forces applied to the mechanical structure. This compliance is due to a lack of precision in the fabrication of the component parts of the machine, and to a lack of rigidity due to a lightweight design. This displacement is of a greater magnitude than the precision positioning tolerance of the apparatus. Consequently, the manipulator may then be displaced outside of the positioning tolerance due to applied forces. However, it is a characteristic of the present invention, that despite the compliance of the mechanical structure of the apparatus, the positioning tolerance will be maintained. The controlled motion is accomplished by the generation of control signals by computer software running on a computer control system. The control software enables the system to run at much greater speeds while not exciting unwanted movement or vibration in the compliant mechanical structure.

Claims36

Dependent claims

An apparatus for achieving precision motion, comprising:

a support structure capable of a degree of compliance;
a manipulator included within said support structure, said manipulator capable of a controlled motion relative to a fixed point, said degree of compliance capable of causing extraneous displacement of said manipulator relative to said fixed point;
a force generating element responsive to a control signal which causes said controlled movement of said manipulator;
and
a control system which generates said control signal thereby positioning said manipulator within a predetermined position tolerance, wherein said extraneous displacement may be greater in magnitude than said predetermined tolerance.

2 more elements

The method of controlling the repeated movement of a manipulator, comprising the steps of:

connecting the manipulator to a support structure, the manipulator capable of repeated movement, the support structure capable of a degree of compliance;
generating a control signal;
controlling an actuator based on said control signal, said actuator causing the controlled motion of said manipulator;
and
positioning said manipulator within a predetermined positioning tolerance, said degree of compliance being greater in magnitude than the predetermined positioning tolerance.

2 more elements

Dependencies are inferred from the claim text.

Precision apparatus with non-rigid, imprecise structure, and method for operating same

Life of this patent

Precision apparatus with non-rigid, imprecise structure, and method for operating same

Life of this patent

Abstract

Claims36