Variable speed drive solutions for furniture!

A leading furniture testing specialist is now among the increasing number of industrial companies benefitting from variable speed drive solutions from Emerson.

To meet these challenges, Advanced Furniture Testing developed specialised machines for tests that include chair back durability, drop impact and load ease, multi-task furniture, dual arm durability and universal cyclic testing.

For a brand new multi-axis chair testing machine, the company is now using the Control Techniques Unidrive M range of drives. The drive’s precise control and accuracy was identified as critical for a brand new machine designed to test chair strength and rigidity.

The machine is designed to complete multiple, repetitive cycles of pulling on the back of the item and pushing on its seat. The pull is completed using a motor that controls an electromechanical actuator, while the push on the seat again is completed using another electromechanical actuator that pushes a load on to the seat. Millions of cycles can be performed to replicate the sit, lean and recline process.

Advanced Furniture Testing ensures each test is performed to the highest level of accuracy and repeatability. The company’s machines use load cells to ‘close the loop’ between the machine and the product under test.

In practice, this means that Advanced Furniture Testing does not just trust a theoretical load applied with a pneumatic cylinder to a pre-set air pressure, for example. Nor does it apply a cyclic dead weight load that may oscillate wildly and apply more loading cycles. Instead, electromechanical actuator/servo systems are deployed similar to those used by industrial robots. This strategy helps to apply a load within two per cent accuracy, far exceeding BIFMA standards which require five per cent accuracy.

The Unidrive M700 drives used on the new machine control the motors, which in turn control the electromechanical actuators. Unidrive M700 offers comprehensive position feedback and high performance control of dynamic permanent magnet servo motors, as well as on-board Ethernet, which gives Advanced Furniture Testing more flexibility, remote programming and data logging.

The drive is paired with a Control Techniques MCi210 machine control module, which adds a powerful, second on-board microprocessor for high performance IEC 61131-3 based machine control.

Douglas Woodard, UL Furniture Division Leader at Advanced Furniture Testing, said: “M700 is just a beautiful machine that delivers everything we need. We selected the Unidrive M for its precise control and accuracy, on top of its reliability and simplicity. We haven’t been disappointed. Furthermore we now plan to use M700 drives for all future machines, and will upgrade our own in-house test machine to feature this innovative technology.”