Parallelized Distributed Embedded Control System for 2D Walking Robot for Studying Rough Terrain Locomotion

Abstract

Biped robots present many advantages for exploration over mobile robots. They do not require a continuous path, which allows them to navigate over a much larger range of terrain. Currently, bipeds have been successful at walking on flat surfaces and non-periodic rough terrain such as stairs, but few have shown success on unknown periodic terrain. The Jaywalker is a 2D walker designed to study locomotion on uneven terrain. It is a fully active robot providing actuation at every joint. A distributed, parallelized, embedded control system was developed to provide the control structure for the Jaywalker. This system was chosen for its ability to execute simultaneous tasks efficiently. The two level control system provides a first level to implement a higher level control strategy, and a second lower level to drive the Jaywalker's systems. The concept was implemented using the Parallax Propeller chip for its relative fast clock frequencies and parallel computing functionality. The chips communicate over a new variation of the I2C bus, which allows multiple slaves to listen to information simultaneously reducing the number of transmissions for redundant data transfers. The system has shown success in taking steps with open loop control. The success of the step is highly dependent on the initial step length using open loop control, but this dependency can be eliminated using closed loop control. The robust structure will provide an excellent platform for uneven terrain locomotion research.