Knee constraint effects of bipedal walking by Visual-lifting Approach

Recently, a lot of biped robots are being investigated and developed. Although humans walk with their knees extending, humanoid robots walk with their knees bending. Walking with their knees bending has advantages that it is not needed to consider the complex models such as toe and heel, and the area of bottom of foot can increase to keep walking stable. However, walking with knees extending can reduce energy and be closed to natural walking. Moreover, length of stride can also increase when knee is full extended. Therefore, it is necessary to make humanoid robot with knee constraint to extend the knee in walking. In this paper, we make humanoid robot with human´s knees structure which has a constraint of knee joint angle motion through simulation and investigated its influence to humanoid walking.