The objective of the application is to create an architecture that simplifies motion control programming, offering fast pick & place transfers and supporting different types of motor.
The implementation that uses the Prodigy Motion Cards Stand-Alone for each of the modular units of the Pick & Place machine solves many problems.
The three axes ‘gantry’ type of the pick & place machine have both “S” ramps profiles and a feed-forward type control, allowing gentle movements and very dynamic at the same time.
The possibility to downlaoad the software in the motion control cards allows to free the host PC from the control of the individual cards, for the benefit of the overall management of the application.
The PMD Motion library can be used to develop code that works on motion card, independently of the host PC, and allowing to dedicate the host PC to the application software for managing the machine. C-Motion is the basis on which the programming code is developed.
It allows the machine engineers to quickly develop the motion control of their applications, using standard programming C/C++.
A suite of software tools is provided with the Prodigy Motion Cards in addition to C-Motion, to facilitate the creation and download of the software in a PC. These utilities include a programming editor, a compiler, a tool for the download and a tool for debugging.
The addition of “S” ramps profiles can significantly reduce the vibration produced by the normal trapezoidal profiles. This implies significantly higher transfer speed.
Often, only a small amount of jerk (“S” ramp in the transition between acceleration and the absence of acceleration) can significantly reduce the induced vibration.
The shape of the “S” ramp will depend on the performance required by the specific system. The Prodigy Motion Cards that include the Magellan Motion Processor can also handle trapezoidal profiles, velocity control with “on the fly” parameter change and electronic axis as an alternative to profiles with “S” ramps.
Adding the speed and acceleration feed-forward at the position loop minimizes the following error without excessively increasing the PID values. This minimizes the risk of the control loop to become unstable and increases significantly the performance of the system. In a pick & place application this allows quicker profiles and therefore higher production capacity in each module.
The Prodigy cards support different types of motor, DC brush, brushless DC, stepper and pulse & direction amplifiers as well. Each axis of a card can be a different type of motor, for example Brushless DC motor with ball screw or linear motor.
This allows the optimal selection of the motor in the system, for both cost and performance. Therefore, the system can be simplified using linear motors, and thus avoiding the need for a dual encoder configuration. Figure 1 below shows three brushless DC motors and a stepper motor controlled by a Prodigy motion control card.