Content area
Full text
Introduction
Automated motion guidance systems with heavy-duty load capacities are experiencing a significant increase in demand. One reason for this revolves around the installation of flexible multi-axis robots onto long tracks. This allows engineers to greatly extend the work envelope while taking full advantage of a robot controller's seventh axis.
For many applications, a linear motion guided gantry system can accomplish the same tasks as a multi-axis robot while incurring less cost. Additionally, these gantry systems can be designed and supplied to end-users from standard heavy-duty subassemblies or components and can be tailored to the specific application.
Related Making accurate measurements on large gantry machines
Robotics Chills Out with Cold-Weather Palletizing Robot Series
Pallets Move on Customizable Conveyor
Here's a look at five highly configurable systems that can be used in gantry configurations for factory floor automation in place of sophisticated robots. Let's start by reviewing some of the basic gantry concepts.
Low to Medium Precision
Factory automation does not always require a high degree of precision. In many cases the task involves heavy products and awkwardly shaped or off-balanced materials. Most applications require high repetition, extended operating time, and long-lasting durability with minimal maintenance. Frequently, the requirement for precision positioning is low (Fig. 1).
Pick and place applications can require low precision when palletizing cases or placing the next item into the production queue. Material transfer applications may involve relocating products with an overhead robotic manipulator from one area to another. XYZ gantry robots (the Z-axis refers to the vertical direction) can position and reposition materials anywhere within a three-dimensional space or enable operations on many faces of a work piece. Spraying systems may require low precision over long distances to paint a rail car or airplane wing.
Heavy Duty Z-Axis
When moving a product, the first order of business is lifting that load. Great care is often taken in the design of end-effector grippers used for manipulating the product. A simple vertical lifting or lowering machine can be referred to a Z-axis system (Fig. 2).
After the item is lifted and supported by the system, all motion will generate additional loads due to accelerations of the mass. Significant loads may be generated during high-speed motion. Speed is typically determined based upon cycle time...