Inverter plays a vital role in any electronic application. And robotics is no different.
Inverter plays a vital role in any electronic application. And robotics is no different. Today, many electronic devices have components that require different power. This requires the introduction of a power conversion stage capable of providing multiple output voltages with varying power levels in both voltage and current levels.
Previously, most power converter stages were built using ad-hoc solutions based on discrete components. Designers need to implement an integrated solution that uses a single IC to perform all the requirements for a power converter. Integrated solutions provide high reliability. Better thermal management and reduction in size and weight than modular equipment based solutions.
Power density drives mobile robot applications
An example that demonstrates the need for energy-dense power converters is robotics. Robots have many electronic components that require different power supplies. These include motors (BLDC and stepper types), servo motors, processing units (microcontrollers or microprocessors), various types of sensors (accelerometers, gyroscopes, pressure, temperature, humidity sensors and others), wireless interfaces (Bluetooth) for control and remote monitoring . , Wi-Fi, etc.), and other sensors and actuators based on the specific application. These power supply networks are very complex.
Highly integrated programmable components such as the latest microprocessors require very low supply voltages, while sensors and communication peripherals operate at higher voltages. Power consumption increases further when driving electric motors. So it is not difficult to find robotics applications that require 4, 5 or more different busbars.
In the case of small battery-powered robots, power converters that can provide multiple power supplies are needed to maximize battery autonomy.
OLogic is a catalyst for the robotics revolution
Innovation in robotics lags quickly. This momentum has been measured by advances in electronics and the availability of open source software libraries that can efficiently implement complex algorithms such as SLAM (simultaneous location and mapping).
Among the companies that have played a major role in designing and marketing robots for industrial, residential and commercial applications, we have to mention Ologic. Headquartered in Santa Clara, California, Ologic is an electronics consulting company with more than 18 years of experience bringing customer robotic designs to market. His extensive robotics experience supports electrical, mechanical and industrial engineering as well as software and firmware engineering.
“We prototype for our customers,” says Ted Larson, CEO of Ologic. “We have a whole group that can handle all aspects of robotic design.” This includes information on power electronics integration, an important design factor affecting the mobility, functionality and battery life of a mobile robot.
Larson says the robotics industry often views electronics as an afterthought. They think they can get away with buying all the ready-made hardware devices and hooking them together. However, it quickly becomes a house of cards.
Mobile robots have specific power requirements and require different levels of power. Sensors, servo motors, actuators, data servers, communication systems, and other components that power the robot require different power quantities and power densities. Some of these components consume a lot of power while others work only occasionally. This requires the ability to deliver energy quickly, cleanly, and inexpensively from battery-powered sources.
Dusty Robotics (Dusty) is a client working with Ologic to improve the power profile of its robots. Based in Mountain View, California, Dusty manufactures robotic equipment for the modern construction industry.
The Dusty Fieldprinter (Figure 1) is a robotic device that transfers construction drawings directly to the construction site floor, thereby reducing planning time and rework costs through accurate and complete floor layouts.
“When you design a building from a CAD model, it’s all in a digital format,” says Phil Hargett, founder / CTO of Dusty Robotics. Today, the current process is to take a digital model, print it on paper, take it to the construction site and have someone on the ground interpret it for themselves.
Dustin has created a device that takes pictures and makes highly accurate prints on the ground, replacing the manual process with a digital one.
The product is extremely accurate, achieving an accuracy of 1.5mm or less. According to Dusty, achieving that kind of accuracy is challenging and requires a lot of sensor fusion in the robot. The system also receives data from external and internal sensors. All this information is collected to give very high localization accuracy, so that the robot knows its location and facing direction at all times.
Energy management is the main technical challenge of the robot. Being a battery powered system, it should provide as much battery life as possible. Dusty explains that robots have many different power fields and must efficiently convert many different voltages from the battery voltage. The sensor is accompanied by the complete printing mechanism which also needs to be set to the desired voltage. Finally, the robot must operate in employment settings, where it is mechanically and electronically adapted to many different weather conditions.
Vicor’s power converters
For this mobile robot, Ologic chose power converters from Vico, more precisely the Vicor ZVS buck and buck/boost regulator series.
Partnering with Vaiko Corporation, Ologic has taken a modular approach to building power distribution networks (PDNs) for robots. Ologic realized that it could not do something with the same operational, thermal and range efficiency as the Vicor power module. Like the ZVS buck regulator, Vicor modules have an efficiency rating of 97% and provide 200 to 300 watts of power, making them very cost effective.
According to Logic, the required power converters must be able to buck and boost depending on the state of charge of the battery and provide constant power on certain power rails regardless of the state of charge and any others. The device has voltage rails.
Vicor’s ZVS buck and buck/boost switching regulators (Figure 2) give designers the flexibility for high power density and high efficiency point-of-load DC-DC control. Integrating a high-performance Zero Voltage Switching (ZVS) topology, it improves point-of-load performance and delivers up to 98% power efficiency.
“Vaiko ZVS Bucks are becoming our favorite way to solve all kinds of power distribution problems because of the price and they just work,” says Larsen. Designing a robot is very, very complex. And power is tricky so we only use reliable Waco power modules for almost all designs.
Additionally, ZVS power converters exhibit no thermal issues, according to Orologic. Due to their high energy conversion efficiency, they develop very little heat for large energy conversion.
Ologic streamlines the prototyping process, allowing their customers to bring it to market faster. Today, Dusty is poised to revolutionize the fieldprinter manufacturing industry, thanks to LOGIC’s support and ability to design power electronics systems.