Robotic Picking
There are many factors to consider when choosing the best robotic solution for your picking application. Most organisations, however, list throughput as their priority. To achieve optimum throughput the picking solution must be fully integrated with the other processes as well as being capable of achieving the speeds required.
Robot manufacturers list their specifications including cycle times, yet speed is also dependent on a number of other factors,
including:
. The weight of the product
. The fragility of the product
. The number of axis movements involved in product transfer, including
orientation and rotation
. The complexity of product placement, including a change in orientation
. The degree of movement required
Consider a heavy yet robust product. Although it can easily be picked, acceleration and deceleration are
determined by the capability of the gripper to hold the product securely. If the transfer required is of
considerable distance, the robot arm must achieve the necessary speed quickly in order to maximise
throughput. This, in turn, demands fast acceleration and deceleration. In this instance, the recommended
solution may involve the use of secondary securing mechanisms on the gripper.
Now consider the situation in reverse. Imagine a robot that has to transfer a light
yet fragile product at high speed. An entirely different gripper design using suction may provide the best approach. Slow attachment and careful detachment
are ensured without compromising on fast acceleration and deceleration. 
When evaluating the real cost of picking, that is, how quickly you can recoup the cost of
automating your picking operation, total throughput is a crucial metric in that calculation. Further consideration must
be given to how easily your software can be reprogrammed: if products leaving the
conveyor are frequently changing advance planning is essential to ensuring product
changeovers are achieved in the minimum time possible. And, if a change of tool or gripper is required, how seamless is the process.
The level of cleanliness required in your operation can also influence the overall
speed of your throughput. The solution may be as simple as selecting a robotic system built to withstand frequent washing; alternatively, you may need to
consider sterilisation of the arm-end tooling between picking, if cross contamination is an issue in your plant.
Space can also affect throughput. Many smaller
robots are capable of handling products of
reasonable size or weight if space is a real consideration, but a more substantial robotic
system will guarantee that optimal movements and speeds are achieved. In addition, some
products require complex grippers that may, themselves, be of considerable weight, an
important factor when assessing the overall weight capacity of your chosen robotic system.
With careful advance planning, an automated production line incorporating vision, picking and packing can be fitted into an
incredibly small space - much smaller, in fact, than a similar manual operation.
When planning from scratch, up to 50% of space can be saved. If space isn't a concern, however, a larger dedicated cell guarantees maximum throughput for
your picking process.
Machinery Automation & Robotics
1/101 Derby Street
Silverwater NSW 2128
Phone: (61) 2 9748 7001
http://www.machineryautomation.com.au