IR Sensors

Kinect

Kinect has some limitations as obstacle avoidance sensor:

  • Narrow fov (58° x 43° horizontal x vertical)
  • Death zone on the first 45 cm
  • Cannot detect glass walls
  • Cannot detect polished metallic surfaces

We dealed with this in our waiterbots adding to them a 11 IR sensors half ring, pointing 12 degrees downward.

  • Sensor model: Sharp GP2Y0A21YK
  • Power supply: Kobuki’s 5V, 1A
  • Sensor reading: Arduino MEGA 2560
  • PC interface: Arduino custom firmware – Bosch adc_driver
  • Mounting: 3D printed frame.

The analog output of sensors is read by the Arduino board, while for power and ground they are connected to Kobuki’s 5V 1A power source. Connecting several sensors to the same power supply makes readings very noisy when there aren’t obstacles. The solution was to put decoupling capacitors on each sensor. For interfacing Arduino, we use Bosch adc_driver. A funny problem comes sometimes when looking at corners in a particular angle (~30 degrees) : sensors get a spurious reading, no idea why. We just went on with this, as is not a common problem.

Different mounting frames are available for downloading and printing in our file server:

  • Horizontally mounted MaxBotix’s LV-Maxsonars
  • Horizontally mounted Sharp IR sensors
  • 12 degrees downward pointing Sharp IR sensors

And here is the result:

kobuki_psd_array_brk_110.png

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This post was last modified by leechangyong on 2016년 1월 11일.

This article has not been revised since publication.

This post was created by 거북이 on 2015년 7월 21일.

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