Robot Throughput, Automation And Robotics, Liquid Handling
In Liquid Handling Robots that are properly balanced, the gantry robot utilization reaches close to 100%, meaning the robot is almost always moving. In such a situation, improving the move times of the robot can lead to significant throughput enhancements. In systems were (one of) the process steps is a gating factor, the designer should attempt to add parallel process steps to increase throughput. We have measured the move times on a Liquid Handling Robot using a number of different approaches and motion profiles for a robot-limited case. The handling system is able to execute complex moves by injecting a new move profile, while an existing profile is being executed. If the system is aware of clearance heights, it is possible to initiate a move in the X/Y plane while a Z move is ongoing. Further, by employing an S-curve motion profile on all axes, a higher acceleration can be achieved with equal or better jerk than comparable trapezoidal velocity moves. The exchange time of the Liquid Handling Robot can be improved by 25%, compared to a system that does not take into account clearances, and by 50% over systems that do not take advantage of combining planar (X/Y) moves.
This article (and poster) shows how we have implemented a high-speed motion system on a Liquid Handling Robot gantry that is aware of system clearances so that it can start a planar (X/Y) move while a Z axis move is still ongoing. By employing such a motion control solution, robot move times can be improved by 25% over conventional robot moves and over 50% compared to systems that only employ single axis moves.
To learn more, please download the full article and poster below.