Product news: November 2001
`Near perfect` servos suppress the vibes
Mitsubishi claims that its latest servo drive is "near perfect". Positioning times for the MR-J2 Super servo have been reduced to 0.9ms, compared to the 5ms achieved by the MR-J2 on which it is based. The servos are targeted at applications where the axes exhibit high inertia and friction, and at installations with low mechanical rigidity.
The servos use a new range of processors that more than double the gain crossover frequency, from 250Hz to 550Hz, resulting in short cycle periods and high response rates.
Permanent online vibration reduction is built into the amplifiers. A specially developed Active Vibration Suppression System (AVSS) determines the resonance points and stops vibrations from escalating. Any vibration that is detected is suppressed using a filter and the vibration damping factor is calculated and adjusted automatically. The AVSS will even detect and correct shifts in the resonance point caused by fluctuating loads and by systems as they warm up.
The servos, which span ratings from 50W to 7kW, also incorporate real-time auto-tuning which is said to provide continuous optimisation of performance for most servo applications, including suspended loads and high-friction applications. An RS-422/RS-485 port allows multi-drop installations of up to 32 stations.