Loading...
Please wait, while we are loading the content...
Similar Documents
Theoretical three-and four-axis gimbal robot wrists
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Barker, L. K. Houck, J. A. |
| Copyright Year | 1986 |
| Description | In high-performance flight simulations, a four-axis gimbal system allows all possible rotations with acceptable gimbal angle rates while it avoids the so-callled 'gimbal lock' that occurs when gimbal rotational axes are colinear. In this paper, pertinent equations (including quaternions) are assembled for a hypothetical robot wrist, functionally equivalent to this four-axis gimbal system, and also for a true three-axis gimbal robot wrist. These equations are used to simulate the rotation of a robot hand by the robot wrist in response to operator rotational velocity commands to the robot hand. Near gimbal lock (wrist singularity), excessive rotational rates occur. Scaling the rates, which is necessary for the three-gimbal robot wrist to prevent rate limiting, introduces an undesirable time delay in the robot hand rotation with respect to the commanded rotation. However, the merit of the four-gimbal robot wrist is that the fourth gimbal angle keeps the robot wrist away from the singularity so that the robot hand moves exactly as commanded. It appears that in a 'worst-type' maneuver of the robot hand, the fourth gimbal angle can be defined so that none of the gimbal angle rates exceed about twice the commanded rates. |
| File Size | 1078848 |
| Page Count | 44 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19860015697 |
| Archival Resource Key | ark:/13960/t4gn3362t |
| Language | English |
| Publisher Date | 1986-05-01 |
| Access Restriction | Open |
| Subject Keyword | Cybernetics Wrist Gimbals Quaternions Automatic Control Manipulators End Effectors Artificial Intelligence Remote Handling Robots Flight Simulation Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
