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[DPRG] Video of Drone Contolled by BeagleBOne Black Running APM Pilot Software

Subject: [DPRG] Video of Drone Contolled by BeagleBOne Black Running APM Pilot Software
From: Doug Emes dougemes at gmail.com
Date: Fri Feb 6 15:50:30 CST 2015

Queen bees, hunter seekers, pathfinders, "Bob", insert other more accurate
description that media will ignore.

On Fri, Feb 6, 2015, 3:47 PM David Anderson <davida at smu.edu> wrote:

> It's too late.
>
>
> On 02/06/2015 11:38 AM, Dennis Clark wrote:
> > Am I the only one that cringes when people call these quad and hex
> copters "drones?"  Can we move away from this media term with such heavy,
> negative military connotations?
> >
> > My rant for the day,
> > --
> > Dennis Clark
> > While traveling
> >
> >> On Feb 6, 2015, at 10:31 AM, ed at okerson.com wrote:
> >>
> >> You can download it here:
> >>
> >> http://software-dl.ti.com/codegen/non-esd/downloads/download.htm#PRU
> >>
> >> Ed Okerson
> >>
> >>> Dick,
> >>>
> >>> Good find.  Haven't watched it yet, but this phrase caught my eye:
> >>>
> >>> "There's a C compiler for the PRU."
> >>>
> >>> Any details?
> >>>
> >>> dpa
> >>>
> >>>
> >>>> On 02/04/2015 12:27 PM, Dick Swan wrote:
> >>>>
> >>>> This is interesting 48 minute video
> >>>> <https://www.youtube.com/watch?v=2Twl2mQAh6g> from the lead developer
> >>>> of APM Pilot. It was given at a LINUX conference. He was describing
> >>>> the successful results of running APM code on LINUX.
> >>>>
> >>>> Here's my comments on some topics in the talk indicating the
> >>>> approximate time in the video that it occurred.
> >>>>
> >>>> 4:38 Live demonstration of a drone / airplane controlled via LINUX
> >>>> port of APM Pilot on a BeagleBone Black (BBB). The drone was at an
> >>>> airfield some distance from the conference location and watched a
> >>>> video as it took off, flew to way points and autonomously landed.
> >>>> LINUX console was remotely running on the overhead screen along with a
> >>>> video (Skype call) of the plane.
> >>>>
> >>>> 6:38 Drone was compiling LINUX kernel at same time as flying. On the
> >>>> BBB the kernel compile takes 5-6 hours because of relatively "low
> >>>> powered" CPU) when dedicated to this task. The compile time increases
> >>>> when APM is also running to around 10 hours.
> >>>>
> >>>> 1,200 SPI transactions per second from IMU in this application (i.e.
> >>>> simultaneous  APM Pilot and Kernel compile). Elsewhere he mentions 4K
> >>>> SPI per second.
> >>>>
> >>>> Uses a BBB "Cape" (similar to a Arduino "Shield") to provide the
> >>>> navigation sensors. Several BBB Capes now exist that contain the
> >>>> appropriate navigation sensors (i.e GPS and IMU and barometer). For
> >>>> example, the successful NavIO Cape from Kickstarter; and recently
> >>>> announced NavIO+. Plus several more Capes from others. Most (all?)
> >>>> were introduced in the last year.
> >>>>
> >>>> 20:21 Uses inline waits for sending 20 byte SPI packets. Better
> >>>> (faster?) than DMA because DMA setup has too much overhead.
> >>>>
> >>>> 22:05 Why use "user space driver" instead of kernel drivers? Answer:
> >>>> Same driver source code used on LINUX as on Arduino APM! Same drivers
> >>>> run on different OSes! It wasn't explicit but it seemed the user space
> >>>> drivers were for SPI and I2C; it was unclear if the low level SPI/I2C
> >>>> hardware control was in kernel space.
> >>>>
> >>>> 24:00 Future will see many of the current I2C sensors (gyro, accel,
> >>>> compass, GPS) migrate to CAN Bus.
> >>>>
> >>>> 24:58 Describes how APM handles real-time critical threads -- they're
> >>>> described as LINUX "FIFO scheduled real time task" with pages locked,
> >>>> predefined stacks, etc for best performance. There's six critical
> >>>> tasks that run in APM.
> >>>>
> >>>> 27:15 Some problems with "jitter" on the long duration nominal 20
> >>>> millisecond loop.
> >>>>
> >>>> キ19 of 2M loops (i.e. a 11 hour run) were over 30 msec. This was the
> >>>> same run APM with LINUX kernel compile in background. 18 of these were
> >>>> under 50 msec. Easily handled by APM Pilot since all the calculations
> >>>> running on the 20 msec loop adjust for the actual loop time rather
> >>>> than assuming it is "precisely" 20 msec.
> >>>>
> >>>> キLongest time was 1.7 seconds. This is a bug. Possibly writing to SD
> >>>> Card with interrupts disabled and waited too long.
> >>>>
> >>>> 31:20     Two things need microsecond timing; i.e. servo pulse input
> >>>> and PWM servo pulse output. Solution uses the 200 MHZ simple PRU
> >>>> (Programmable Real-time Units) on BBB. PRUs have direct access to GPIO
> >>>> pins. I think PRUs are on-board the CPU chip. PRUs have shared access
> >>>> to the BBB memory. There's a C compiler for the PRU. Total source code
> >>>> for the PRUs is 300 lines.
> >>>>
> >>>> 37:00 Description of latest Outback challenge competition held Oct
> >>>> 2014. It's a "search and rescue" autonomous drone looking for a human
> >>>> (via image recognition) at an approximate GPS location 6 miles away.
> >>>> Drone needs to fily to approximate location, search for the human and
> >>>> then drops a water bottle to the human. APM team won the competition.
> >>>> Many of the other entrants used chunks of APM code.
> >>>>
> >>>> 38:30 Picture of image recognition from Outback challenge. It looks
> >>>> similar to the images you see from a CMU Cam where color blob is
> >>>> highlighted with a rectangle overlaid on the camera image. I'm amazed
> >>>> at how the image recognition found a human shape from the air.
> >>>>
> >>>> Some of the new sensors drivers in development for integration with
> >>>> APM include.
> >>>>
> >>>> キOptical flow sensors
> >>>>
> >>>> キLaser range finding. Pointing downward for containing altitude.
> >>>>
> >>>> キUse Android quad-core (i.e. lots more CPU cycles) and then do image
> >>>> recognition using increased processing power.
> >>>>
> >>>>
> >>>>
> >>>> _______________________________________________
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