[magicsmoke]

Looks like Kylin OS uses the Linux kernel. While not impossible to use in a real-time application (SpaceX Falcon 9 uses it) there's definitely work involved in stripping it down enough to work as an RTOS. NASA Perseverance uses VxWorks instead, which was designed from the beginning as an RTOS. VxWorks is also proprietary and looks like it's US export restricted.

8 ms isn't hard to hit. 8 ms with 100% reliability is.

[edrxty]

What?

8ms is incredibly slow for realtime systems. A difficult target for a control system would be three orders of magnitude lower than that on a full size OS like linux.

VxWorks is being partly phased out too, last I heard wind river was pushing people towards their own linux based offering. Speaking from experience it's absolutely miserable to develop on because of the licensing model and reliance on the Eclipse IDE. If you need a low level system FreeRTOS/CMSIS is a far better option and if you want linux compatibility (frequently just the convenience of ssh and rsync) just use real time linux.

[nine_k]

I suppose what is slow directly depends on the hardware. On a 10 MHz CPU, 8 ms = 80k clocks, which is not necessarily easy to hit consistently, because of critical sections and scheduling overhead. On a 2 GHz CPU, 8 ms can as well be the normal slice of the scheduler.

I suppose the CPU on this machine may be severely underclocked because of the power requirements.

[edrxty]

My question isn't really in response to the specifications of the rover but rather the inaccuracy of the above statements.