MESSAGES SCHEDULING OF CAN-BASED NETWORK FOR A HUMANOID ROBOT

This paper deals with the messages scheduling of a CAN (Controller Area Network), which is based on the distributed control scheme to integrate actuators and sensors in a humanoid robot. For a humanoid robot to implement distributed processing, each control unit should have an efficient control method, and fast calculation and valid data exchange capabilities. A preliminary study revealed that CAN has better performance and is easier to implement than other networks such as FIP (Factory Instrumentation Protocol), VAN (Vehicle Area Network), etc. Since a humanoid robot has to process all the control signals from many actuators and sensors, communication time limitation is dependent on the transmission speed and data length of CAN. In this paper, the CAN message scheduling is proposed for a humanoid robot under the conditions of jitter-present message group, high load of messages over the network, and transmission errors. In addition, the worst-case response time was compared with the limitation time given by the simulation algorithm. The proposed message scheduling can guarantee the CAN limitation, and be used to generate the walking patterns for a humanoid robot.