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Parts fix and replacement

Frame

  • Frame is made from ABS resin using 3D printer
  • But instance glue for ABS to adhere broken frames is much easier than remaking frame with 3D printer.

Leg

  • Leg is made from ABS resin using 3D printer

Propeller

  • Part number is HCB-03 and available from the following shop.

http://www.hobbyking.com/

  • Drilling the center of propeller is needed to extend hole to fit 1.5mm shaft length. By extending the hole with the following 1.44mm reamer, a propeller can be fit to a shaft of the motor without adhesive.

http://www.micronradiocontrol.co.uk/prop-gws.html#prop-reamer-1.5mm

  • By default, HCB-03 propllers are very unbalanced and causes vibration. To solve this problem, tape adhesive can be used to calibrate moment balance.
  • After replacing a propeller, parameters of thrust bias should be set by changing following variables in /root/dirs/pc/code/base/pxlib.c
    //Set following varibales, normally ranging from -120 to 120.  
    //This setting strengthen left thrust(to go right)  
    addr_pconfig->duty_bias_upper = 0;  
    addr_pconfig->duty_bias_lower = 0;
    addr_pconfig->duty_bias_left = 60;
    addr_pconfig->duty_bias_right = -60;
    After changing those variables, the program must be compiled again.(see User Program Manual)

Motor

  • Part number is AP-03 and available from the following shop.

http://www.overskyrc.com/

Sonar sensor

  • Part number is LV-MaxSonar?-EZ1 and available from the following shop.

http://www.maxbotix.com/

  • The sonar sensor is very weak to vibration cased by Phenox(Impulse noise is observed without gel tape).

Micro SD card

  • Part number is TS4GUSDC4 at kickstarter model in May 2014.
    • Boot successful rate of the current model depends on micro SD card part number.(known issue)
  • save backup with following command (replace sdd and path to fit user's environment).
    sudo dd if=/dev/sdd of=~/sdback.dd
  • copy backup to new micri SD card with following command(rewite /dev/sd* and path to fit user's environment).
    sudo dd if=~/sdback.dd of=/dev/sdd bs=1024k

Maintainance

  • Phenox needs maintainces after some flight.Please check following points
  1. Tighten 18 screws of 4 motors(12 screws), the camera(2 screws), 4 legs(4 screws).
  2. Sonar location and cable disconnection check.
  3. Check sensor state using tutorial_selfstate(see Tutorials)
  4. Save backup of micro SD card.(see here)
  5. Check propellers are not loose.
  6. Check motors rotate smoothly.

Known issue

Boot from micro SD card fails irregularly.

  • This problem is caused by dependency of Phenox firmware system and micro SD card.
  • We observes two cases that boot fails.
  1. Red led doesn't turn off (before executing u-boot)
  2. Reading sector error of MMC (when u-boot reads contents of micro SD card)

Incomplete images are sometimes acuquired (green images)

  • This problem seems to be caused by miss-synchronization between camera and Phenox, and is under examination.
  • This issue depends on initialization states, so if users acquire normal image from both cameras, image acquisition is normal until shutdown.
  • Self position estimation becomes very slow(insensitive to self-movement) when this problem occurs.

Impulse noise is observed in mic.

  • This signal is caused by sonar sensor, which is sending ultrasonic signal to measure height.
  • Will be fixed at next revision.

Wrong height control.

  • The source of this problem is mostly sonar sensor.
  1. Impulse noise caused by vibration
    • Users can check this noise by monitoring selfstate(see tutorial_selfstate of Tutorials)
    • inserting gel-tape improves this problem.
  2. Stationaly wrong height value
    • Check connection of a sonar sensor.
    • In our experiment, some sonar sensors are broken with direct physical shock such as dropping Phenox on the ground without legs.

Attach file: fileleg.stl 654 download [Information] fileframe.stl 768 download [Information]

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Last-modified: 2014-09-07 (Sun) 22:58:22 (1532d)