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Robot Delivery

Stephan Kloss, Jon Shephard, Duncan Hand

Overview

Usage of robots for manufacturing applications in the automobile, printed circuit board and aerospace industry became standard practice during the last two decades. However, most of these systems are linear 6-axis or 4-axis SCARA (Selective Compliant Assembly Robot Arm) robots, comprising of a single arm with motorised joints which provide the required degrees of freedom, these systems are also known as SERIAL ROBOTS.

An alternative design is the PARALLEL ROBOT, where the end effector is connected to the base via multiple kinematic chains. Any two chains thus form a closed loop. This is opposed to classical open loop mechanisms such as the serial robot (e.g. articulated robots such as jointed arms).

  • Disadvantages of serial robots: low stiffness, accumulated errors, have to carry actuator weight
  • Parallel robots potentially offer; increased accuracy, reduced weight, cheaper construction
  • Already implemented fibre optics into parallel manipulator for 3D ms cutting

Concept

  • Integration of commercially available ms or ns laser into parallel robot;

  • Laser is fibre coupled;

  • Effector optics housing integrated into motion system to allow 3D movement of laser focus spot relative to workpiece

  • Output of fibre imaged with effector optics fixed in custom built housing;

  • Gas nozzle can be used for assist gas (ms processing);

  • Third axis acts as focus control.

   

Figure 1: Through-cut stainless steel sheet, 300 mm thick with cut star shape in place (left) and, removed (middle). The scale markers are 1mm. A closer detail of the cut is given in (right) where the white square has 1mm sides.

 

Figure 2: Integration of ms laser (via optical fibre) into parallel manipulator.

 

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