How to record robot odometry in multiple bagfiles after resetting the robot's computer without resetting its odometry and timestamps?

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Hello, been a while since I checked ROS Answers, but here are some additional ideas:

• It may be possible to "hot-swap" the batteries without shutting it down, if two (discharged) batteries are able to continue powering all the equipment on the robot. Just replace them one at a time. If using multiple sets of batteries, it's generally a good idea to keep them in "matched" sets. If you're buying new batteries it is now possible to get slighly higher capacity SLA batteries in that form factor; we switched from 7Ah to 9Ah batteries starting a few years ago. There might be higher capacity ones also available now.
• The skid-steer P3AT with its very wide high friction tires is not very efficient when turning. You can replace the wheels with other wheels (but you need to change firmware calibration and ARIA parameters), or just cover the wheels with some tape with less friction. Or drive the robot on sand or dirt (which is it's original design intention.) I used to keep a bucket of sand and sometimes put it on the pavement in the area I was using a P3AT.
• I don't know about offsetting timestamps. Maybe there is a tool somewhere that can process the contents of the later bagfiles and do this? There is a function in the ARIA library for applying an offset to the odometric pose I don't recall exactly how rosaria will handle that, and there isn't a rosaria interface for it, but you could add it. The ARIA method is ArRobot::moveTo()). If there is a standard or typical ROS command for this kind of thing, it should be used. Connect with the rosaria project on github to discuss. There is a robot firmware command (SETO) to reset odometry to 0,0,0 but there isn't one to initialize it to any arbitrary pose. (The MobileSim simulator has one, but not the P3AT robot firmware.)