Technology Supporting Robotics
The technology supporting robotics is making great strides. Major developments are in software, vision guidance and lighter weight, but stronger structures. The software to define the motions of the robot is more user friendly. Also, most users are more comfortable with using software.Vision technology also,has made great strides to become user friendly and more vision guided robots are on the market.Many robot parts, such as the arms are made from light weight, reinforced materials, making them lighter and stronger
The robot has fewer moving parts than a similar electric/mechanical deviice. The MTBF of robots over 60,000 hours.For material handling such as palletizing or loading product into trays and cases, robots can be the ideal solution.To do the reverse, unloading pallets or containers, robots can handle odd shaped or fragile products better than mechanically actuated fixtures.
Material handling robots come in three formats, 4 axis SCARA, 6 axis articulated arm and 3 axis Gantry. The 4 axis SCARA robot is ideal for pick and place motion with short vertical travel. For some time vision guided SCARAs have picked select items out of large groups and placed them into programmed container locations. ( Picking chocolate pieces off a conveyor and placing them into predetermined tray locations has been an example for a number of years. Now they do it faster and at a lower cost.).The capacity of SCARAs is maximum around 10kg. Most models are less than 5 kg. However, they are fast and,depending on the part weight, can pick-and-place 20 to 30 pieces per minute. SCARAs also have great placement precission.
The 6 axis articulated arm type robots come in 5kg to over 500 kg capacity models. Their reach can be over 2 meters. Depending on the load and path of motion, they can handle up to 35 – 40 products an hour.Because of the higher load capacity, the articulated arm robot can move more than one product at once. Grippers, (end effectors) can grab a group of sorted items and lift them into a container or position at once.
Gantry robots have a gripper that moves on X-Y tracks with limited motion in the Z direction.They are fast,precise in location repeatability and capacity up to 50 kg. The limitation is that they are intended for a specific layout of max X and Y direction.The main negative point with robots is SAFETY. The robot arm will move through its programmed path regardless of any obstruction. Fencing and safety sensors are required to meet OSHA and other safety standards.The safety standard ANSI/RIA R15.06 – 1999 Section IV Chapter 4, is the primary guideline for the user of robots.