Drives & Controls September 2022

n TECHNOLOGY September 2022 www.drivesncontrols.com 16 NIDECHAS DEVELOPED a technology for detecting the position of motor rotors that, it claims, combines the high accuracy of optical encoders with the low costs and component counts of magnetic encoders. Nidec and its Nidec Sankyo subsidiary have incorporated the patented technology into an AC servomotor that has a resolution of 17 bits, and a maximum accuracy of better than ±0.02 degrees. The motor is aimed, in particular, at applications requiring high precision and responsive controls, such as industrial robots and AGVs (automated guided vehicles). It has traditionally been difficult to detect rotor positions in brushless DC motors accurately due to inconsistencies in the mounting and sensitivity of magnetic sensors – especially Hall sensors. Nidec has developed an algorithm that corrects these inconsistencies, improving the position-detection accuracy using general-purpose microcomputers. Conventional optical and magnetic encoders both have strengths and weaknesses: n Despite optical encoders ’high accuracy and their ability to operate in strong magnetic fields, they can be expensive because of their installation costs and need for code wheels and other components. Also, their performance can deteriorate in adverse environments where dust or oil are present. n Magnetic encoders can operate reliably is such environments and are cost- effective because they work with a relatively inexpensive chips, but their accuracy is lower than that of optical devices. Like magnetic encoders, Nidec’s new Zignear sensors need few components – only a Hall- effect device and a general- purpose microcomputer. They detect rotor positions using a magnet attached to the motor in combination with software. Their tracking capabilities are said to be similar to those of optical encoders. In tests, the sensors are said to have achieved position accuracies of better than ±0.1 degrees in temperatures from –40 to +125ºC. The sensors have the same ring shape as a magnetic encoder, making replacement easy. They have an outer diameter of around 30mm and are about 2mm thick. They can output ABZ pulses, like optical encoders, as well as serial data, voltage and PWM signals, which are common with magnetic encoders. Nidec says that it has demonstrated that an AC servomotor equipped with the Zignear technology can power an AGV with a similar accuracy to a conventional 17-bit AC servomotor. It has also tested a stepper motor equipped with the technology in a sewing machine application where the motor feeds cloth using repeated high-speed forward and reverse rotations. The company says the sewing machine operated normally and demonstrated a high- speed response. Nidec is planning to test the technology in other applications such as industrial robots and power tools. https://www.nidec.com/jp/techno logy/capability/zignear “Nidec says that it has demonstrated that an AC servomotor equipped with the Zignear technology can power an AGV with a similar accuracy to a conventional 17-bit AC servomotor.” Nidec says that its AC servomotor fitted with the Zignear position-sensing technology performs with a similar accuracy to a conventional 17-bit AC servomotor. THE NETWORKING specialist Belden has announced an edge gateway device which it is hailing as“a revolution in operational edge computing”. The Hirschmann OpEdge-8D is designed to unite IT and OT (operational technology) data from sensors to the cloud. Belden says that with the rise of IIoT and the increasing number of connected devices, manufacturers are faced with an excess of data. Many are ill-equipped to manage the data and analyse it to create useful insights. The new device promises a secure, reliable way to connect operational systems with information systems. It is said to give organisations a new way to run applications that manage and analyse large amounts of data and create insights that can optimise production and boost efficiency. Belden says that the OpEdge-8D is “unique” in the way that it: n deploys applications (containers and virtual machines) at the network edge to provide insights into areas such as operational efficiency and maintenance; n simplifies the deployment of applications across edge devices to enable scalability and to drive productivity; and n provides a protected link to the cloud with secure remote access. “As the number of connected devices increases, driven by the IIoT, many organisations struggle with a way to leverage massive volumes of data for smarter, more effective management of operational processes,” explains Jeremy Friedmar, a senior product manager for edge systems at Belden. “The OpEdge-8D leverages the latest IT technologies to streamline the process of bringing local operational data to where it can be integrated quickly into applications that will produce insights that ultimately improve efficiency, maximise uptime and enable continuous process improvement.” https://drivesncontrols.news/iv0gjy n Next-gen edge gateway helps manufacturers to cope with flood of data Technology combines the best of optical and magnetic encoders