2D Interpolation: Lines, Arcs, and Circles

Many applications for high-precision linear stages are primarily concerned with accurate positioning, and it's not critical to know the position between points. Zaber's linear stages with integrated controllers work very well for these applications in single or multi-axis set-ups. They also work well when predictable and precise motion is needed in a single axis.

Sometimes a user will have a requirement for multi-axis motion with predictable and complex paths that independent controllers can't meet. With the interpolated movements introduced in firmware version 6.12 of Zaber's two-axis X-MCC2 controller, Zaber's devices now have the capability to meet these needs.

Figure: X-MCC2 two-axis universal motor controller

Figure: G-LSQ gantry demonstrating interpolated motion

The stream set of commands can coordinate the smooth and accurate movement of XY systems in lines, arcs, and circles. These can be combined to make more complex shapes, while also controlling the speed and timing, and coordinating with other devices through input and output control.

One type of application where this type of movement is critical is in Computer Aided Manufacturing (CAM). While Zaber's stages are not currently suitable for the loads of large milling or lathe machining, other CAM applications such as water-jet cutting, micro-welding, 3D printing, laser etching, or adhesive applying are now possible with this feature.

Controlling digital outputs also allows you to activate tooling during movement seamlessly. For these CAM applications, the command set for interpolated motion has been organized in an analogous system to G-code (a commonly used command set for CAM). Converting numerical controlled (NC) programs to Zaber commands is straightforward, and software to facilitate this will be released.

Inspection systems also benefit from interpolated control. Rather than following an arbitrary path between two points and waiting for both axes to reach a destination, the X-MCC2 sends each stage on the most direct path. Triggering digital outputs also makes it possible for sensors or cameras to capture data more quickly and easily. For applications where a grid of locations needs to be scanned, you no longer need to accelerate and decelerate from point to point when capturing data. Scanning along straight edges that aren't aligned with an axis, or along curved edges, is also much easier to accomplish.

Many applications that require accurate or predictable timing benefit from the new stream command set as well, even single axis applications. The commands queue together so that the execution of them is determinate. Cycling applications, for example, can benefit from the streamed commands as it reduces any gap between cycles that's usually required for communication.

You can email contact@zaber.com to speak with our engineers if you have any questions, or think that your application could benefit from interpolated motion.