Automation and Logic Control

Introduction, 23.02.2001

This lecture is dealing with controlling and supervising prothesis and other aids for handicapped people. Controlling means that an exact command is given to the machine, e.g. "go to koordinate x=20, y=0, z=50", whereas supervising deals with general commands, e.g. "bring me to the kitchen".

An overview of the laboratories was given:

• Laboratory 06

  Projects:

  • Artificial Wrist:

    The mechanical part consists of the wrist and three fingers. The movement of the fingers is controlled by the signals of myo-sensors. These sensors are located on two pads, these pads are placed on two muscles of the patients arm. Upon moving the muscles an electrical charge is created. The amplitude and amount of charge is depending on the force of muscle-movement.
    
    

  • Robot ULYSSES

    The aim of this project is to develope a source of transportation for strongly handicapped people. The robot features different sensors:
    • optical sensors: they give a rich signal with precise information, but it may take a long time to compute this information.
    • accoustical sensors: they give a rather poor signal with little information, but enough to make a "0/1" decision.
    So far the robot can be moved by different means:
    • movement controlled with keys of computer keyboard
    • movement according to a programm previously written and stored in the computer.
    For the future other means of supervising are planned.
  
  
  

• Laboratory 08

  This laboratory is equipped with robots of different kinds as well as test-stands for ultrasound sensors. The test-stand for ultrasound sensors the range and Streubreite. The sensors will be used for some experiments during this course. Also in this laboratory there is a 3D-measuring device for measuring the shape of a spine. The arm of this device is moved by the operator along the spine of the patient. The data (3D-coordinates) is recorded by a computer as a list of numbers. Until now there is no graphical visualisation available. This laboratory is equipped with webcams
  
  

• Acceleration Sensor

  The acceleration sensor used in this laboratory is a common sensor which is used in many technical applications (e.g. airbag). The sensor is connected to a PC, which allows measuring of several movements of the sensor and the correlated acceleration. The data is shown in numbers as well as graphically. An acceleration sensor could be a useful feature in an artificial wrist: when moving the wrist quickly in an emergency situation (e.g. to hold on to the railing when stumbling) the signals of the sensor would be high and could tell the fingers to close as tight as possible.

  Technical Data of the Sensor:

  • Evaluation board with ADXL202, Microchip 16C63
  • two axis aquisition of acceleration or tilt information
  • PC Data aquisition software
  • 275HZ max. sample rate
  • RS-232 Port
  • datalogging capability
  • IC socket location for verifying ADXL202 devices