RON - "Roboter ohne Namen"

(the robot formerly known as Camera And Enhanced Sensor controlled Autonomous Robot)

 

 

Currently we are developing an autonomous robot called RON II which is equipped with visual and sensory abilities. Here both a stereo camera pair as well as several ultrasonic sensors and infrared sensors are used.

Based on the RON testing platform the following diploma theses were accomplished:

Technical data:
  • structure built from steel tubes holds all robot components
  • 6 wheels (3 on each side are are coupled by a toothed drive belt, no steering mechanism)
  • driven by windshield wiper motors (worm gear provides very high torque on low revolution speed, power consumption up to 25W per motor)
  • data processing on AMD Duron 1200 PC-system (standard mini-ATX-board using special power supply, power consumption up to 70W)
  • robot hardware controlled by two Atmel AT90CAN128 microcontrollers (8bit RISC, AVR series).
  • CAN bus communication system (bus system used by the automotive industry; allows priority packets, etc.) for microcontroller-PC-communication.
  • PCAN-USB CAN bus adapter.
  • Linksys wireless LAN router running OpenWRT (56Mbit, for remote controlling and supervising)
  • 2 WinTV-Go framegrabbers to read images from the stereo camera
  • driven by car battery (operational for 3 hours in normal conditions)
  • Various sensors, see next section.
Sensors
  • a home-made omnidirectional camera system consisting of a door peephole, a standard lens and a CCTV camera
  • a stereo camera enables us to extract 3d-information from images (how), it consists of two CMOS-videocameras (manufactor GKB) which are mounted fixed to a camera head
  • 12 infrared distance sensors (Sharp GP2D12 - since GP2D02 is no longer available) (range 10cm to 80cm, the sensors emit light pulses and calculate distance by taking transit time reflected signal; large coverage; accuracy in the range of centimeters, if light beam is not absorbed)
  • up to 8 ulrasonic sensors (Devantech SRF08) (range 3cm to 6m, the sensors emit sound pulses and calculate distance by taking transit of the time reflected signal; large coverage; accuracy in the range of centimeters; can record up to 3 peaks, but you have to dealk with multiple reflections)
  • 2 odometry sensors (to measure rotation of wheels) encoder discs with line markings pass a photo sensor
  • electronic compass (Devantech CMPS03) measures heading of the robot using two perpendicular mounted hall sensors to measure the tangential component of the earth's magnetic field (accuraty: +/- 20 degrees)
  • muRata Gyrostar gyroscope measures the turn rate of the robot when driving curves

While the video sensor covers only the environment in front of the robot, we have mounted infraread sensors round the robot to detect obstacles in all directions:

We considered upgrading RON with several new sensor types:

  • bumper could be used to stop the robot if it accidentially impacts into an obstacle