Towards an integrated society

The fourth major type of motion controller is the integrated motion card. In this approach, shown in figure 4, the amplifiers are integrated directly onto the card. This combines the easy synchronization capability of multi-axis motion cards with the reliability advantages of drives.

Integrated motion card

Intelligent Motion Modules

A big advantage of this approach is easy servicing and very low cost, since there are no separate amplifiers to purchase. The main disadvantage is that the motor drive power levels tend to be low, since high switching voltages and heat are difficult to combine reliably with sensitive digital logic circuitry. Another important consideration is that the total number of possible combinations of motion computing platforms, amplifier power levels, and motor types, is extensive. Because of this, integrated motion cards tend to be designed for a specific application, rather than purchased off-the-shelf.

Such a custom card design can be a major undertaking, because algorithms for profiling and servo loop closure can be complex. The availability of off-the-shelf motion processor ICs greatly simplifies the task however. These ICs, available from a number of vendors, provide built-in functions such as trajectory generation, servo loop closure, commutation, and other functions.