In this paper, a simple oscillator-based biped walking method is described and a CORDIC-based FPGA hardware design method is proposed to effectively generate a walking gait in a biped robot. Based on the simple oscillator-based model, some equations represented by sinusoidal functions are proposed to describe a biped walking as a complete walking process with three modes (starting mode, gait cycle mode, and ending mode) and six phases. In these six phases, these oscillation parameters can be represented by the swing length, the step length, and the lifting height of the biped robot. Then an FPGA hardware structure based on the CORDIC operator named circular rotation is proposed and implemented on an FPGA chip. Finally, some comparison of the proposed CORDIC-based FPGA hardware method and the software method are presented. We can see that the proposed hardware method significantly reduces the processing time to generate gait trajectories of a biped robot.
Journal of the Chinese Institute of Engineers 38(5), pp.610-620