Schunk’s compact LWA 4 Powerball robot arm can manipulate loads half its weight

The Schunk LWA 4 Powerball arm, with a weight/payload ratio of 2:1, is believed to be one of the most high powered lightweight arms in the world. At a dead weight of 12 kg, it can dynamically handle loads of up to 6 kg and has a gripping radius of more than 700 mm. The compact design front end or wrist joint means it can be easily manoeuvred in restricted spaces. Its repeat accuracy of 0.06 mm provides for high process stability for demanding measuring and testing tasks. Also, the intelligent design prevents dangerous crushing and shearing movements, making it safe to use around people. Central elements of the lightweight arm are three compact ERB Powerball modules, which combine the movements of two axes. The entire electronic control and regulation circuitry is integrated in the joint drives. Position, speed and torque can be flexibly regulated. An innovative quick-change system with integrated signal feed-through allows for fast and easy commissioning of the gripping system. Since the supply lines for the gripper and tools are completely within the module, there are no interfering cables on the peripheral devices. Universal communication interfaces and cable technology for data transfer and power supply enable the arm to be quickly and easily integrated into existing control concepts. The manipulator is supplemented by an industrial robot controller with an integrated CoDeSys PLC. A handheld control panel with a touchscreen display facilitates teaching and instruction. The 24 V DC supply voltage enables mobile use as well as use at different locations. Consistent lightweight construction and state-of-the-art torque motors keep the energy demands of the lightweight arm down to an average of 80 W. As a consequence, energy costs are lower, rechargeable batteries require less frequent recharging and small-format batteries can be used.