Increasing power demands for robots
While many experts believe we are on the precipice of a robotics revolution, robots have in fact existed for over 2,000 years. The first robot was a steam-powered pigeon, which was created by ancient Greek mathematician Archytas and was designed to study how birds fly.
Although the concept has existed for some time, the types of robots that exist today are far more complex then Archytas’s original creation. This is in terms of both the design and their purpose. For example, 70 per cent of industrial robots are reportedly used in the automotive, electrical and machinery industry. The science fiction representations of robots have been known to spark fear among the public but, with improved features and technological advancements, it appears more businesses are in fact investing in the robotics market.
In 2016, North America ordered 24,606 robots alone. Costing $1.9 billion, the investment was a ten per cent growth from the figures reported in 2015 and the demand doesn’t appear to be disappearing. The International Federation of Robotics (IFR) has forecasted that the number of robots to be deployed worldwide will increase to 2.6 billion units by 2019.
One of the biggest drivers influencing the demands for robots is the internet. E-commerce retailers like Amazon are well known for their automated distribution centres, which deliver products safely and efficiently to customers. In fact, Slice Intelligence reported that, in 2016, 43 per cent of all online retail sales in the US went through Amazon. Accounting for the largest market share with four million online purchases, it’s not difficult to see why more logistics companies are turning to robotics to retain a competitive edge.
Outgrowing existing technology
Although robots reduce operational costs and speed up various tasks carried out on the factory floor, this isn’t possible without the correct power source. Batteries are the main component of a robotic system and as original equipment manufacturers (OEMs) create more intuitive robots, the power demands for these devices become significantly greater than many existing power sources.
Mobile robots, for example, feature various sensors and processors, in addition to higher-current actuators. Each of these demands a high volume of power. Loss of power in a robot can be problematic for several reasons. The first being that, in the event of power failure, a robot can lose its calibration and mastering values.
Calibration governs the set parameters in the kinematic structure of a robot, such as the relative position of joints, tool-centre-point (TCP) positions and joint lengths. For robots used in the medical sector, calibration is fundamental to the robot’s accuracy — especially if operating on a patient. This means that the engineer must manually re-programme the robot controller once power returns and before resuming operation. This takes valuable time away from production and potentially reduces revenue costs.
Battery considerations
To overcome this problem, engineers should ensure that the robot has a suitable backup battery integrated into its system. The range of primary, non-rechargeable, Lithium Thionyl Chloride and Lithium Manganese Dioxide cells and batteries from Ultralife Corporation, for example, provide long term power to a robots control system. Integrating batteries like this means that if power is lost, any critical configuration information is safely retained.
Another important consideration when selecting the right battery for a robotic application is whether it features smart functionalities like Ultralife’s UBI-2590 MGPP product range. The range combines Ultralife’s SmartCircuit technology and SMBus v1.1 interface to provide pertinent battery information. Available in three variations, the range features a Lithium-ion version of the battery, which can communicate with compatible devices and chargers to provide accurate runtime predictions, safety indications and maintenance optimisation. This is part of the battery’s management system (BMS), which protects the cells from issues like over-voltage, under-current and short-circuit.
The range also features dual LCD displays, which indicate the absolute state of charge of each battery. This allows the operator to easily monitor the robot so that they know when to shut down or recharge the battery. This improves on the traditional voltage cut-off management that most batteries rely on and provides a more predictable performance. Most batteries will also include smart features that broadcast its charging voltage and current requirements to a compliant smart charger. This technology ensures fast, efficient and safe charging because it is the battery that is in control of the process.
Energy and durability
While ensuring the robot doesn’t lose power is an important concern for engineers, so is the durability of the chosen battery. This characteristic applies to the mechanical structure of the battery and its lifetime cycle. Batteries with higher energy capacity tend to have shorter life cycles. The latest high energy Lithium-ion cells, for example, may only operate for a few hundred cycles. This is not an ideal fit for a logistics bot, which would be required to operate 24 hours a day, seven days a week. Instead, design engineers can integrate Lithium Iron Phosphate batteries. The chemistry features lower energy but can run up to more than 2000 cycles in a cyclic application making it a suitable fit for robotic applications in various sectors.
Powering the future
As robotic developments continue to advance at a phenomenal rate and into new markets, OEMs and design engineers need to make sure they are using the right power source for their device. Unlike Archytas’s steam-powered pigeon, the power requirements for industrial and service robots can vary drastically.
Whether it’s a guided autonomous vehicle (GAV) in a factory, or a wheeled-platform robot for moving shelves and pallets, the cost of downtime from robots like these can be substantial to a company’s production. Powering the robot should, therefore, be a core focus for OEMs.
About the author:
Michele Windsor is global marketing manager of battery specialist Ultralife Corporation – www.ultralifecorporation.com
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