Drive System Reliability and Trouble shooting April 29, 2006 Championship Atlanta, GA Jay TenBrink and Patrick Major Goodrich H.S. Martians 494 and More Martians 70 DaimlerChrysler and General Motors. Agenda. Introduction (why we are here) Drive system reliability Trouble shooting
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Drive System Reliability
and Trouble shooting
April 29, 2006
Jay TenBrink and Patrick Major
Goodrich H.S. Martians 494 and More Martians 70
DaimlerChrysler and General Motors
Manager – FWDPT Chassis Engineering
Team 494 Engineering Coach since 2001
Owner – Major Distributing Co.
Team 494 Head Coach since 2001
My Favorite Robot
Team 494 Head Robot since 2003
Drive system reliability
Examples of actual electrical and mechanical problems
When, where, and why they occurred (we won’t say who)
Trouble shooting techniques (root cause analysis)
Safety precautions and root cause analysis do’s and don’ts
Helpful analysis tools
Corrective action implementation
Appropriate repairs and avoiding collateral damage
Verifying the fix
Design and construction methods for reliability
Basic DFMEA (Design Failure Mode Effects and Analysis)
Many of the drive system fundamental issues we address can be applied to other robot systems (arms, claws, etc.)
“It is good to learn from experience. It is better to learn from someone else’s experience”
What follows is a somewhat comprehensive list of actual problems that we have experienced first hand or witnessed during our last four years with the FIRST program.
13.Don’t begin to implement corrective actions before you have determined the root cause.
14. Do try to duplicate the failure mode after the corrective actions are in place to verify your fix.
1. Emergency corrective actions (containment)
2. Long term corrective actions
Long term corrective actions cont’d.
3. Avoiding collateral damage during analysis / repair
4.Verifying the fix
Note: This is an analysis tool that is used during the design stage.
1. Apply the KISS principle (keep it simple, silly)
2. Don’t design in cascading failures (like in our example)
3. Layout your wiring neatly and in a naturally protected area. If it must be routed in a severe area, protect it.
4. Label both ends of each wire, both power circuits and control cables. This will assist you in diagnosing issues and will save you time in the long run.
5. Protect exposed components from damage with metal guards or lexan.
6. Positively secure your battery in the robot and tie wrap the power cables together prior to each match. In every regional at least one robot has a battery fall out.
1. Terminals must be properly crimped to achieve a solid mechanical and electrical connection. Do a pull test on several of your samples. Crimping is the chief source of problems.
2. Terminals need to be the proper size and screwed down tight at the device.
3. Make sure you meet or exceed the wire gauge sizes specified.
4. Make sure wiring is not routed over sharp edges, in pinch zones, or areas where it will be bruised, stretched, or cut.
5.Soldering of terminals should not be necessary if they are crimped properly. Soldering can temporarily mask a poorly crimped terminal.
6.When routing wiring through tubing, or in any enclosed area, be careful not to drill through it.
7.Check for continuity from the battery to the frame (grounding out). before powering up your robot for the first time.
1. Create an inspection check list to go over every time the robot returns from a match to find damage & wear.
2. Exercise all robot features for proper function after the robot has been: shipped, idle overnight, repaired, modified, etc.
3. Keep a log of all repairs and modifications to your robot: damage, wear, regular service, modifications, etc.
4. Establish a battery maintenance and charging procedure with one person assigned to be in charge.
This presentation will be posted on the Martian website: