CANopen in non-industrial robots

CAN Newsletter March 2009

The company Telerob used CANopen servos and motors to develop a remote controlled EOD robot for investigating dangerous areas from a safe distance and diffusing explosive charges. It can be used, for example, on aeroplanes with a suspected bomb on board. The CAN network is used to communicate closely with the modules. The CANopen protocol was crucial in helping make the development of the device quicker, simpler and more modular. The axes are largely controlled on a time-independent basis, which means that the bus performance easily meets requirements. The use of CANopen technology means that sub-modules, such as apprehension arm or drives, can be used modularly for other products. CANopen technology helps simplify the use of mechanical interfaces. The largest drives are located in the four drive tracks, which are each fitted with a 40-mm diameter DC motor with braking and encoder. Smaller motors with sensors are used in the seven-axis manipulator with an adjustable tower. Nine drives in the 5-W to 150-W output range are used in total, all controllable by the corresponding motion controller. All controllers are linked together in a network via a CAN network. A real-time computer is used as the NMT master, controlling not only the drives but also the operation terminal and camera. Information is transmitted via a radio interface so that the robot can work without wires. The four-chain drive, axis manipulator and tool change system are served by the operation terminal. The EOD robot is battery-powered and can be used completely autonomously for a wide range of tasks thanks to its high efficiency.