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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: Dennis Clark dlc at frii.com
Date: Sat Feb 7 14:40:25 CST 2015

I am not judging!  ;-)

--
Dennis Clark
While traveling

> On Feb 7, 2015, at 8:31 AM, David Anderson <davida at smu.edu> wrote:
> 
> Well, I routinely refer to my helicopter is "my robot."  
> 
> But that's mostly because I'm getting old and can't remember which toy I'm playing with. 
> 
> dpa
> 
> 
>> On 02/06/2015 05:26 PM, Dennis Clark wrote:
>> I prefer to not be silently complicit with media sound bites and herd mentality. 
>> 
>> We, at least can do better. 
>> 
>> Can't we?
>> DLC
>> --
>> Dennis Clark
>> While traveling
>> 
>> On Feb 6, 2015, at 2:50 PM, Doug Emes <dougemes at gmail.com> wrote:
>> 
>>> 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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