Determining Positions
First Claim
1. An apparatus for determining the position of an element that is movable within a frame of reference, wherein a multiplicity of first targets are fixed relative to the movable element, and a multiplicity of base elements are provided at fixed positions relative to the frame of reference, the apparatus comprising a measurement system including means movable with the movable element, the measurement system comprising means for determining the position of the movable means relative to at least some of the base elements, and for determining the position of at least some of the first targets relative to the position of the movable means.
2 Assignments
0 Petitions
Accused Products
Abstract
The position of a movable element such as the end of a robot arm (10) which has several degrees of freedom, being mounted on a base (11) and including a wrist mechanism, is determined by installing a multiplicity of base targets (32, 74) around the base of the robot, and a multiplicity of arm targets (42, 74) around the base (14) of the wrist mechanism (15), and an optical means (90) that moves with the movable element to determine the positions of at least some of the base targets and of at least some of the arm targets. The optical means may be a laser tracker or a camera system (90), and it may be mounted on the part (13) of the robot arm to which the base (14) of the wrist mechanism (15) is connected. This enables existing robots (10) to achieve absolute positional accuracy relative to a fixed external frame of reference.
-
Citations
17 Claims
- 1. An apparatus for determining the position of an element that is movable within a frame of reference, wherein a multiplicity of first targets are fixed relative to the movable element, and a multiplicity of base elements are provided at fixed positions relative to the frame of reference, the apparatus comprising a measurement system including means movable with the movable element, the measurement system comprising means for determining the position of the movable means relative to at least some of the base elements, and for determining the position of at least some of the first targets relative to the position of the movable means.
-
14. (canceled)
-
17. A method for determining the position of an element that is movable within a frame of reference, wherein a multiplicity of first targets are fixed relative to the movable element, and a multiplicity of base elements are provided at fixed positions relative to the frame of reference, the method utilising a measurement system including means movable with the movable element, the method comprising determining the position of the movable means relative to at least some of the base elements, and determining the position of at least some of the first targets relative to the position of the movable means, and hence determining the position of the movable element.
Specification