Drives & Controls June 2022

n TECHNOLOGY June 2022 www.drivesncontrols.com 18 IGUS HAS ANNOUNCED a smart cobot (collaborative robot) which costs just €4,970 (£4,230) and can be up and running in a few days. The plug-and-play cobot – part of the company’s Rebel family – weighs just 8.2kg. It is claimed to be the lightest of its type, due largely to the fact that around 90% of its mechanical components are made from engineering polymers, including “the world's first industrial-grade cobot gearbox made of plastic”. The cobot’s payload is 2kg, its reach is 664mm, and its repeatability ±1mm at seven picks per minute. It is aimed at industrial applications such as pick-and-place and quality control, as well as emerging applications such as restaurant and agricultural automation. A particular challenge when developing the cobot was how to deal with the heat generated in the integrated strainwave gears, which are affected thermally by the drive motors. “We focussed on larger motors and better efficiency to significantly reduce heat generation,” reports Alexander Mühlens, head of igus’ Low Cost Automation business. “This enabled us to improve continuously and ultimately quintuple the number of cycles to two million – which is equivalent to a normal service life of two years.” The company has also applied its “smart plastics” know-how to the cobot’s power electronics, and developed an encoder with conductive plastic tracks which can measure temperature, current and the number of rotations, cycles and iterations. A cloud- connected camera can be used to generate a dashboard showing all of this data live, allowing users to track key indicators such as wear, cycle time and quantities in real time as the cobot is operating. Igus will be offering the cobot in two variants: n an open-source version without a control system, power supply or software, for €3,900; or n a plug-and-play version, including control software and a power supply, for €4,970. Users can specify strainwave gears in diameters of 80 or 105mm, capable of delivering 3Nm or 25Nm of torque respectively at 6rpm, with 50:1 transmission ratios. The cobot can be bought via igus’ RBTX online marketplace, along with compatible hardware and software from more than 40 partner suppliers, with the assurance that everything will be 100% compatible. Items available include cameras, grippers, motors, sensors and control systems. Igus is aiming to simplify robotic integration even further with new offerings and business models. “We will provide an app store where low-cost automation vendors and software developers can contribute their software ideas,” explains Mühlens. “By leveraging existing software, users can implement their automation even faster.” www.igus.eu/product/ 20962?artNr=REBEL-6DOF-00 €4,970 plug-and-play cobot is 90% plastic and can move 2kg The American motors and controls manufacturer Teknic has been awarded a US patent for a method of dissipating energy recovered from mechanical loads connected to servomotors during braking. It says that this function – which it calls VRS (vector regen shunt) – will simplify servodrives by eliminating the need for external regenerative circuits and shunts, thus cutting costs, space requirements, wiring and system complexity. Motors often perform braking operations where kinetic energy is transferred from a load to the motor. This regenerative energy can be captured when decelerating connected loads, using hoists to lower loads, retracting loads from compressed springs, and so on. The regenerated energy is returned to the motor’s inverter circuitry and transferred to a DC voltage bus in the motor drive circuitry. In AC-powered applications, the regenerated energy is typically returned to a capacitor bank. But capacitors have energy storage limitations, so machine designers either have to reduce the amount of kinetic energy produced, or get rid of the excess regen energy elsewhere. Traditionally, the most common way of doing this has been to direct the excess energy into a resistive load and convert it to heat. However, this adds complexity and costs. Teknic’s VRS function dissipates regenerative energy using the motor’s windings to manage the energy. In many applications, it will allow a servomotor to be used without any external regenerative components, according to the company, cutting system costs, wiring and complexity. Teknic is offering the function on its ClearPath integrated servomotors. It is enabled as simply as clicking a checkbox. https://www.teknic.com n Patented regen function simplifies servodrive apps igus says that its Rebel cobot can be commissioned in a few days at a low cost Teknic is offering its new braking energy dissipation function on its ClearPath integrated servomotors