Without today’s cost-efficient industrial machines the feasibility of technology, ideas and quality-of-life-improving products would be impacted significantly. Furthermore, we often rely on machines, with their precision control and durability, to undertake tasks that are simply outside the physical capabilities of human operators or that could endanger their lives.
Robotics is just one element of manufacturing automation that continues to grow and develop. Robots designed to collaborate with their human counterparts, known as cobots, have also drawn significant interest as the safety barriers that have typically separated robots and humans are torn down. At the beginning of its journey in industrial automation is the Autonomous Guided Vehicle (AGV).
Logistics centres and manufacturing sites benefit from their ability to collect and move materials around factories and storage facilities without human interaction. With a public keen to consume customised rather than standardised mass-produced goods, AGVs can move workpieces from workstation to workstation in whatever order necessary to create unique products, breaking the one-size-fits-all conveyor belt approach.
While manufacturers expect suppliers of industrial automation equipment to continuously improve the capabilities of their systems, they are ultimately dependent on the semiconductor industry to implement these innovations. As industry experts collaborate at global and national levels to define new communication standards or power topologies, semiconductor vendors need to participate with their technical insight as well as undertake the investment-intensive design, qualification and manufacture of the resulting devices needed. Specific and generic trends, from both customers and market segment research, have to be considered. Continued focus on energy efficiency across all sectors demands semiconductor vendors search for possible solutions and improvement in their semiconductor fabrication processes, hardware devices as well as approaches that can only be implemented in system software.
Implementing efficiency
With production machinery often running 24/7, the increase in robots and cobots, and the introduction of battery-powered AGVs, efficient drives are crucial. The latest driver devices for stepper motors from Toshiba deliver significant gains while providing equal functionality by implementing an Automatic Gain Control (AGC) feature.
In order for stepper motors to hold their position historically a constant current was applied to ensure that enough torque was available for all operational situations. AGC monitors both the current and torque in real-time, applying just enough current in order that the torque can be maintained. This reduces drive current by up to 40% and significantly reduces heat dissipation.
Brushless motors have also established themselves as the alternative to brushed DC motors thanks to their quiet operation, reduced maintenance demands, and lower electromagnetic emissions. The challenge here is that the commutation, previously handled mechanically, transfers into the electronic domain. Toshiba’s development team tackles this issue head on with its Intelligent Phase Control, or InPAC, technology.
InPAC works to synchronise both the voltage and current being feed into the motor, minimising the phase difference, regardless of the RPM of the motor. This requires only a single initialisation of the solution and delivers power reductions of up to 20% when compared to conventional approaches.
In the area of power conversion, the search is ongoing to add single-digit percentage points to efficiency figures. This is understandable bearing in mind that power supplies are often in continuous operation and feature repeatedly in every industrial application. Much of today’s efforts are focused upon reducing the minute losses caused by the switching components integrated into power supply solutions. One such loss is known as the reverse recovery charge (Qrr) stored in the junction of freewheeling diodes. Another manifests itself in the internal parasitic output capacitance (Coss) of switching transistors. A technique known as Synchronous Reverse Blocking (SRB) uses a silicon carbide (SiC) diode in conjunction with a second series transistor to almost eliminate Qrr.
Toshiba has developed the Advanced-SRB approach (A-SRB). This additionally pre-charges the parasitic capacitance mentioned, effectively reducing the impact of Coss by orders of magnitude and results in an efficiency improvement of up to 4% over comparable superjunction-based solutions. Driver ICs such as the T1HZ1F can be combined with Toshiba’s high-voltage 650V DTMOS IV switches with high-speed diodes, and low-voltage UMOS VIII 60V MOSFETs for power factor correction, DC/DC converter applications and even motor drives. A-SRB provides a silicon-based solution that comes close to SiC in terms of efficiency, yet at lower cost with easier access to components.
Ethernet has been the backbone of data networks for PC and servers, providing ever more bandwidth as its standard has developed. However, its variable latency is unsuited to the world of real-time industrial control and automation. International working groups have defined new Time Sensitive Networks (TSN) standards under the umbrella of IEEE 802.1Q that now enable Ethernet to be used in systems requiring fixed end-to-end latencies and high reliability. The support for TSN demands physical changes in the lower layers of the OSI model. These have not always been accommodated on existing MCUs and MPUs and developers may be restricted to upgrading platforms for which the processors have already been defined. The TC9562BXG from Toshiba is an innovative TSN solution that can help in both host and node applications.
As well as implementing a TSN capable Ethernet interface, the TC9562BXG integrates both a PCI express (PCIe) interface and a 32-bit ARM Cortex-M3 processor. In host applications where a powerful application processor might be used, the PCIe interface enables simple integration of TSN functionality where previously none was available. The integrated Cortex processor can also function as a hardware accelerator, undertaking data pre-processing tasks that offload the host application processor. In node TSN applications, the Cortex processor is powerful enough to implement a stand-alone application, while the internal memory resources and range of peripherals ensure that typical industrial applications can be implemented.
Reliable interfacing is an essential element of the IIoT. Optical isolation ensures that systems can be linked and controlled without danger of damage to control and sensing systems and typically need to fulfil UL 1577 and EN 60747-5-5. These are often seen replacing both relays and transformers providing silent operation, higher reliability, and an opportunity to save space. The latest generation of photo couplers, such as the TLP2310, operate at up to 125°C, support data transfer rates of up to 5 Mbps, consume as little as 0.3 mA of current, and are integrated into a 2.1 mm high SO6 package. The latest improvements in the integrated LED light source ensure just a 10% degradation over 100k hours of operation, a 40% improvement over devices featuring conventional LEDs.
Summary
Innovation for industrial systems is intrinsically linked to the advancements in semiconductor technology that suppliers such as Toshiba can offer. While many of the larger step improvements have been achieved, it is the time-intensive research to attain single-digit improvements in efficiency, reductions in latency for legacy networks, and higher levels of reliability that will define the challenges and resulting solutions that we develop.
Author details:
Peter Lieberwirth, VP, Toshiba Electronics Europe
