RECENT developments released with the latest edition of firmware from Kollmorgen, represented by Motion Technologies , now incorporate Rack Drive Panel, an electronic solution to the age-old problem of backlash.
More commonly, today's applications are demanding positional accuracy's counted in arc seconds or microns, hence the necessity for zero-backlash systems.
There are three engineering approaches towards the attainment of this goal: Multi-axis controllers; Direct Drive motors; Rack Drive Panel (RDP).
Multi-axis controllers are mostly employed where several axes need to be controlled, usually relative to one another, or in real-time.
Although system backlash can be removed through the programming of complex algorithms, this solution requires the purchase of additional hardware (usually expensive) and also requires labour intensive programming to commission the working system.
Direct Drive technology is available in both rotary and linear motor systems. Technically this offers the most accurate solution as the motor is directly coupled to the load, thereby producing a mechanically backlash free system.
Although this offers the "best" anti-backlash alternative, motor sizing can get excessively large to match load considerations and therefore may prove to be cost prohibitive.
RDP utilises intelligent firmwave to provide an economical hardware based solution. Implementation is achieved by application of a detailed set-up procedure.
Each servo amplifier utilises its analogue output to provide feedback to the other servo amplifiers second analog input, thus providing closed loop torque control.
Other benefits of RDP include increased load-rotor intertia ratio, automatic compensation for pinion wear and no complex programming of control algorithms.
Typical applications of RDP are telescope and tracking systems, indexing tables, machine turrets, large linear tables.