Good Vibrations Engineering Ltd.

Home Contact FMS Virtual Boss HMI Paper Mechanical concept paper

Monthly Report for Space Robotic FMS PreCommercialization Development October 31, 2017

Summary

Continued data extract and presentation for in report on modes in 3300-6500 Hz range with each of 4 single excitation segments.

Specification

No change.

Design

No change.

Analysis

No change.

Software Simulation

no change

Breadboard Manufacturing

We continue to delay disassembling structure, to identify higher frequency modes.

Breadboard Testing

This months effort has been continuation of identifying and presenting 'best' optimization configuration for particular frequency response at individual accelerometer locations. The visualization techniques to achieve this are improving, but it is still difficult to distinguish closely spaced modes. Not further testing effort will be put to this configuration. It is expected there will be shifts after the structure is disassembled and accelerometers reposition in more secure fashion.

Plans for November.

Finish tech memo on test results for 3300-6500 Hz range testing. Disassemble structure and reapply accelerometers on bottom of loading plate.

What's so tough?

Temperature Lack of atmosphere drives temperatures to be either hot in sun or cold in shade. Robots are for moving things around, so they go into and out of shade repeatedly.

Force not directly measureable. It can be inferred from strain or deflection. Such measures are affected by thermal distorsion.

Large dynamic range linear vs rotation forces. Long robot arms and the need to capture 'free flyers' generates large rotational forces.

High Stiffness A high stiffness requirement, makes measurement of strain or deflection more difficult to isolate from thermal distorsion.

Drift Space operations tend to be slow - often taken over a period of hours.

6 dof It is important to distinguish all 6 degrees of force measurement, but the shear and moment loading cases can produce difficult to distinguish effects