Inexpensive equipment helps with motion control theory

Modern control theory is a fundamental course for undergraduates and post-graduate students, it’s also an active area for academic researchers. By its nature, control theory is highly theoretical, abstract and complex requiring students to have a solid mathematical foundation. To achieve the best teaching outcome, a platform allowing students to simulate and conduct experiments is critical.

Ideally this platform needs to be scalable to meet advanced research needs. Traditionally this requires expensive, inflexible and non-intuitive equipment being acquired and commissioned. For years Dr. Phil Commins, Faculty of Engineering and Information Sciences research fellow at University of Wollongong (UOW), had been struggling to find an ideal platform for academic purpose until he heard of ANCA Motion’s AMD2000 servo drive system.

“Traditionally the experiment platform must consist of a whole set of equipment including DC brushed motor, motor amplifier, analogue controls, data acquisition system and motion controller.” Commins said. “There are many issues with the traditional platform. Firstly, it’s difficult for students or researchers to test their algorithms in real time targets. Secondly, as a pure analogue system the students cannot experience the quantization problems associated with modern digital control systems.” Dr Commins went on to say “Also, testing different load conditions, in the traditional system you have to physically change the mechanical load, which is troublesome and time-consuming as the system consists of numerous pieces of equipment.  It can get quite expensive and non-portable which makes it not suitable for Labs.”

In 2015 ANCA Motion released their latest generation of AMD2000 servo drives. The servo drives are compact in size, reducing the need for costly cabinet space while not compromising on ANCA Motion’s state-of-the-art technology. The EtherCAT-based fieldbus communication enables simple and efficient real-time motion control. The on board I/O’s eliminate the need for separate I/O modules which can be costly. The AMD2000 drives incorporate a certified Safe Torque Off (STO), eliminating the need for an external safety devices and simplifying the safety system integration.

Dr. Commins was convinced that the AMD2000 servo drive system would satisfy his requirements and agreed to work with ANCA Motion on developing a Lab platform based on the AMD2000 drives, targeting advanced control system education and research. The platform consists of a pair of servo motors coupled back-to-back with each motor controlled by an AMD2000 3Amp drive. Between the two motors, one simulates a programmable load while the other works in control mode (e.g. velocity or position). Based on the real-time EtherCAT communication, students and researchers can run Mathworks Simulink real-time target and communicate with drive. This enables students and researchers to experiment with various control models, such as PID and MPC control, digital filter and observer-based controls while utilising industrial servo drives and motors.

“The new AMD2000 based lab platform has been well accepted by the students and research fellows since it has been introduced,” Commins said. “The pure digital system exposes students to the problems that occur in real life industrial environment such as quantization noise and also avoids electrical noise issues and limitation often experienced when using analogue based systems. This allows the focus to be on education and research.”

“One of the big advantages of the AMD2000 based platform is that we can use one motor to simulate various load conditions including linear and non-linear dynamic loads in a safe and repeatable environment, without having to physically change the test rig,” Commins noted. “Thanks to the rich functionality integrated in the compact package, we are able to make this platform portable and for a lower cost. All these factors make it an ideal solution for Lab use.”